Initial Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

LLM Generation

Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

Output

Sure, here is the equivalent function written in C: 

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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int* pivots = (int*)malloc(cols * sizeof(int));
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(rows * sizeof(int));
        used_for_row[i][0] = i; // Initialize with self
    }

    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }
            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }
            if (other < col) {
                extra++;
                continue;
            }
            int* temp_row = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp_row;

            int* temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }
        for (int j = 0; j < cols; j++) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        int* others = (int*)malloc(rows * sizeof(int));
        int others_count = 0;
        for (int i = 0; i < rows; i++) {
            if (matrix[i][col + extra]) {
                others[others_count++] = i;
            }
        }

        for (int i = 0; i < others_count; i++) {
            if (others[i] == col) continue;
            int row = others[i];
            for (int j = 0; j < rows; j++) {
                used_for_row[row][j] |= used_for_row[col][j];
            }
            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[row][j] = (matrix[row][j] - matrix[col][j] * matrix[row][col + extra]) % PH;
                }
            } else {
                while (matrix[row][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[row][j] = (matrix[row][j] - matrix[col][j]) % PH;
                    }
                }
            }
            for (int j = 0; j < cols; j++) {
                matrix[row][j] = (matrix[row][j] + PH) % PH; // Ensure non-negative
            }
        }
        free(others);
        col++;
    }
    for (int i = 0; i < rows; i++) {
        free(used_for_row[i]);
    }
    free(used_for_row);
    free(pivots);
    return matrix;
}

// Helper function to print the matrix
void printMatrix(int** matrix, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int main() {
    int rows = 3;
    int cols = 3;
    int graphlen = 3;

    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3;
    matrix[1][0] = 4; matrix[1][1] = 5; matrix[1][2] = 6;
    matrix[2][0] = 7; matrix[2][1] = 8; matrix[2][2] = 9;

    printf("Original Matrix:\n");
    printMatrix(matrix, rows, cols);

    matrix = rref(matrix, rows, cols, graphlen);

    printf("\nRREF Matrix:\n");
    printMatrix(matrix, rows, cols);

    for (int i = 0; i < rows; i++) {
        free(matrix[i]);
    }
    free(matrix);

    return 0;
}
This C function implements the same functionality as the provided Python function, converting a matrix to its reduced row echelon form (RREF). Note that the `used_for_row` is implemented as a 2D array of integers, where each row starts off containing only its own index. This might need further refinement based on the requirements of how `used_for_row` should be structured and returned.

Extract Code

I extracted the following code from that output: 

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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int* pivots = (int*)malloc(cols * sizeof(int));
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(rows * sizeof(int));
        used_for_row[i][0] = i; // Initialize with self
    }

    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }
            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }
            if (other < col) {
                extra++;
                continue;
            }
            int* temp_row = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp_row;

            int* temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }
        for (int j = 0; j < cols; j++) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        int* others = (int*)malloc(rows * sizeof(int));
        int others_count = 0;
        for (int i = 0; i < rows; i++) {
            if (matrix[i][col + extra]) {
                others[others_count++] = i;
            }
        }

        for (int i = 0; i < others_count; i++) {
            if (others[i] == col) continue;
            int row = others[i];
            for (int j = 0; j < rows; j++) {
                used_for_row[row][j] |= used_for_row[col][j];
            }
            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[row][j] = (matrix[row][j] - matrix[col][j] * matrix[row][col + extra]) % PH;
                }
            } else {
                while (matrix[row][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[row][j] = (matrix[row][j] - matrix[col][j]) % PH;
                    }
                }
            }
            for (int j = 0; j < cols; j++) {
                matrix[row][j] = (matrix[row][j] + PH) % PH; // Ensure non-negative
            }
        }
        free(others);
        col++;
    }
    for (int i = 0; i < rows; i++) {
        free(used_for_row[i]);
    }
    free(used_for_row);
    free(pivots);
    return matrix;
}

// Helper function to print the matrix
void printMatrix(int** matrix, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int main() {
    int rows = 3;
    int cols = 3;
    int graphlen = 3;

    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3;
    matrix[1][0] = 4; matrix[1][1] = 5; matrix[1][2] = 6;
    matrix[2][0] = 7; matrix[2][1] = 8; matrix[2][2] = 9;

    printf("Original Matrix:\n");
    printMatrix(matrix, rows, cols);

    matrix = rref(matrix, rows, cols, graphlen);

    printf("\nRREF Matrix:\n");
    printMatrix(matrix, rows, cols);

    for (int i = 0; i < rows; i++) {
        free(matrix[i]);
    }
    free(matrix);

    return 0;
}

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int* pivots = (int*)malloc(cols * sizeof(int));
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(rows * sizeof(int));
        used_for_row[i][0] = i; // Initialize with self
    }

    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }
            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }
            if (other < col) {
                extra++;
                continue;
            }
            int* temp_row = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp_row;

            int* temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }
        for (int j = 0; j < cols; j++) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        int* others = (int*)malloc(rows * sizeof(int));
        int others_count = 0;
        for (int i = 0; i < rows; i++) {
            if (matrix[i][col + extra]) {
                others[others_count++] = i;
            }
        }

        for (int i = 0; i < others_count; i++) {
            if (others[i] == col) continue;
            int row = others[i];
            for (int j = 0; j < rows; j++) {
                used_for_row[row][j] |= used_for_row[col][j];
            }
            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[row][j] = (matrix[row][j] - matrix[col][j] * matrix[row][col + extra]) % PH;
                }
            } else {
                while (matrix[row][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[row][j] = (matrix[row][j] - matrix[col][j]) % PH;
                    }
                }
            }
            for (int j = 0; j < cols; j++) {
                matrix[row][j] = (matrix[row][j] + PH) % PH; // Ensure non-negative
            }
        }
        free(others);
        col++;
    }
    for (int i = 0; i < rows; i++) {
        free(used_for_row[i]);
    }
    free(used_for_row);
    free(pivots);
    return matrix;
}

// Helper function to print the matrix
void printMatrix(int** matrix, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int __delete_this__main() {
    int rows = 3;
    int cols = 3;
    int graphlen = 3;

    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3;
    matrix[1][0] = 4; matrix[1][1] = 5; matrix[1][2] = 6;
    matrix[2][0] = 7; matrix[2][1] = 8; matrix[2][2] = 9;

    printf("Original Matrix:\n");
    printMatrix(matrix, rows, cols);

    matrix = rref(matrix, rows, cols, graphlen);

    printf("\nRREF Matrix:\n");
    printMatrix(matrix, rows, cols);

    for (int i = 0; i < rows; i++) {
        free(matrix[i]);
    }
    free(matrix);

    return 0;
}



#include<stdio.h>
#include<stdlib.h>

int main() {

int arr0[] = {1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr1[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr2[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr3[] = {0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr4[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr5[] = {0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr6[] = {0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0};
int arr7[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, -30};
int arr8[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr9[] = {0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, -20};
int arr10[] = {1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr11[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr12[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr13[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -14};
int arr14[] = {0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr15[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, -30};
int arr16[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr17[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr18[] = {0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr19[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr20[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr21[] = {0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr22[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, -20};
int arr23[] = {0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr24[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr25[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr26[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr27[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr28[] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr29[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr30[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr31[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr32[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, -10};
int arr33[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr34[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr35[] = {0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -9};
int arr36[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, -20};
int arr37[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, -40};
int arr38[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int* arr[] = {arr0, arr1, arr2, arr3, arr4, arr5, arr6, arr7, arr8, arr9, arr10, arr11, arr12, arr13, arr14, arr15, arr16, arr17, arr18, arr19, arr20, arr21, arr22, arr23, arr24, arr25, arr26, arr27, arr28, arr29, arr30, arr31, arr32, arr33, arr34, arr35, arr36, arr37, arr38};
int** got = rref(arr, 39, 49, 37);


int answer = got[3][0]+got[3][1]+got[3][2]+got[3][3]+got[3][4]+got[3][5]+got[3][6];
int expected = 146;
if (answer != expected) {
    printf("Wrong answer; got %d instead of %d.\n", answer, expected);
    exit(1);
}
printf("All tests passed\n");
}
And got the output: Wrong answer; got 1 instead of 146.

Substring Evaluation

Testing if the previous output contains the string All tests passed: False

Initial Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

LLM Generation

Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

Output

Certainly! Here is the equivalent C function for the given Python code. Note that some operations, like `numpy` array manipulations, have been converted to standard C operations. Also, we need to manage the dynamic memory allocations for the 2D array and sets explicitly in C. 

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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int* pivots = (int*)malloc(sizeof(int) * rows);
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    int* used_for_row_sizes = (int*)malloc(rows * sizeof(int));

    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(sizeof(int) * rows);
        used_for_row[i][0] = i;
        used_for_row_sizes[i] = 1;
    }

    // Modulo operation
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }

            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp_row = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp_row;

            // Swap used_for_row
            int* temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;

            int temp_size = used_for_row_sizes[col];
            used_for_row_sizes[col] = used_for_row_sizes[other];
            used_for_row_sizes[other] = temp_size;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];

        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        for (int j = 0; j < cols; j++) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        for (int i = 0; i < rows; i++) {
            if (i == col) continue;

            int contains = 0;
            for (int k = 0; k < used_for_row_sizes[col]; k++) {
                if (used_for_row[i][k] == used_for_row[col][k]) {
                    contains = 1;
                    break;
                }
            }

            if (!contains) {
                used_for_row[i][used_for_row_sizes[i]] = used_for_row[col][0];
                used_for_row_sizes[i]++;
            }

            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[i][j] = (matrix[i][j] - matrix[col][j] * matrix[i][col + extra]) % PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }

            for (int j = 0; j < cols; j++) {
                matrix[i][j] = (matrix[i][j] + PH) % PH;
            }
        }

        col++;
    }

    for (int i = 0; i < rows; i++) {
        qsort(used_for_row[i], used_for_row_sizes[i], sizeof(int), cmpfunc);
    }

    free(pivots);
    free(used_for_row_sizes);

    return used_for_row;
}

// Comparison function for qsort
int cmpfunc(const void *a, const void *b) {
    return (*(int*)a - *(int*)b);
}
This code translates the logic from the Python function to C, including handling the matrix manipulation and dynamic memory management. Note that `qsort` is used to sort the sets of indices in `used_for_row`.

Extract Code

I extracted the following code from that output: 

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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int* pivots = (int*)malloc(sizeof(int) * rows);
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    int* used_for_row_sizes = (int*)malloc(rows * sizeof(int));

    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(sizeof(int) * rows);
        used_for_row[i][0] = i;
        used_for_row_sizes[i] = 1;
    }

    // Modulo operation
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }

            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp_row = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp_row;

            // Swap used_for_row
            int* temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;

            int temp_size = used_for_row_sizes[col];
            used_for_row_sizes[col] = used_for_row_sizes[other];
            used_for_row_sizes[other] = temp_size;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];

        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        for (int j = 0; j < cols; j++) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        for (int i = 0; i < rows; i++) {
            if (i == col) continue;

            int contains = 0;
            for (int k = 0; k < used_for_row_sizes[col]; k++) {
                if (used_for_row[i][k] == used_for_row[col][k]) {
                    contains = 1;
                    break;
                }
            }

            if (!contains) {
                used_for_row[i][used_for_row_sizes[i]] = used_for_row[col][0];
                used_for_row_sizes[i]++;
            }

            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[i][j] = (matrix[i][j] - matrix[col][j] * matrix[i][col + extra]) % PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }

            for (int j = 0; j < cols; j++) {
                matrix[i][j] = (matrix[i][j] + PH) % PH;
            }
        }

        col++;
    }

    for (int i = 0; i < rows; i++) {
        qsort(used_for_row[i], used_for_row_sizes[i], sizeof(int), cmpfunc);
    }

    free(pivots);
    free(used_for_row_sizes);

    return used_for_row;
}

// Comparison function for qsort
int cmpfunc(const void *a, const void *b) {
    return (*(int*)a - *(int*)b);
}

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int* pivots = (int*)malloc(sizeof(int) * rows);
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    int* used_for_row_sizes = (int*)malloc(rows * sizeof(int));

    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(sizeof(int) * rows);
        used_for_row[i][0] = i;
        used_for_row_sizes[i] = 1;
    }

    // Modulo operation
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }

            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp_row = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp_row;

            // Swap used_for_row
            int* temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;

            int temp_size = used_for_row_sizes[col];
            used_for_row_sizes[col] = used_for_row_sizes[other];
            used_for_row_sizes[other] = temp_size;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];

        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        for (int j = 0; j < cols; j++) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        for (int i = 0; i < rows; i++) {
            if (i == col) continue;

            int contains = 0;
            for (int k = 0; k < used_for_row_sizes[col]; k++) {
                if (used_for_row[i][k] == used_for_row[col][k]) {
                    contains = 1;
                    break;
                }
            }

            if (!contains) {
                used_for_row[i][used_for_row_sizes[i]] = used_for_row[col][0];
                used_for_row_sizes[i]++;
            }

            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[i][j] = (matrix[i][j] - matrix[col][j] * matrix[i][col + extra]) % PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }

            for (int j = 0; j < cols; j++) {
                matrix[i][j] = (matrix[i][j] + PH) % PH;
            }
        }

        col++;
    }

    for (int i = 0; i < rows; i++) {
        qsort(used_for_row[i], used_for_row_sizes[i], sizeof(int), cmpfunc);
    }

    free(pivots);
    free(used_for_row_sizes);

    return used_for_row;
}

// Comparison function for qsort
int cmpfunc(const void *a, const void *b) {
    return (*(int*)a - *(int*)b);
}



#include<stdio.h>
#include<stdlib.h>

int main() {

int arr0[] = {1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr1[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr2[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr3[] = {0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr4[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr5[] = {0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr6[] = {0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0};
int arr7[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, -30};
int arr8[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr9[] = {0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, -20};
int arr10[] = {1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr11[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr12[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr13[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -14};
int arr14[] = {0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr15[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, -30};
int arr16[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr17[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr18[] = {0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr19[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr20[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr21[] = {0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr22[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, -20};
int arr23[] = {0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr24[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr25[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr26[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr27[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr28[] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr29[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr30[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr31[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr32[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, -10};
int arr33[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr34[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr35[] = {0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -9};
int arr36[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, -20};
int arr37[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, -40};
int arr38[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int* arr[] = {arr0, arr1, arr2, arr3, arr4, arr5, arr6, arr7, arr8, arr9, arr10, arr11, arr12, arr13, arr14, arr15, arr16, arr17, arr18, arr19, arr20, arr21, arr22, arr23, arr24, arr25, arr26, arr27, arr28, arr29, arr30, arr31, arr32, arr33, arr34, arr35, arr36, arr37, arr38};
int** got = rref(arr, 39, 49, 37);


int answer = got[3][0]+got[3][1]+got[3][2]+got[3][3]+got[3][4]+got[3][5]+got[3][6];
int expected = 146;
if (answer != expected) {
    printf("Wrong answer; got %d instead of %d.\n", answer, expected);
    exit(1);
}
printf("All tests passed\n");
}
And got the output: main.c: In function 'rref': main.c:122:68: error: 'cmpfunc' undeclared (first use in this function) 122 | qsort(used_for_row[i], used_for_row_sizes[i], sizeof(int), cmpfunc); | ^~~~~~~ main.c:122:68: note: each undeclared identifier is reported only once for each function it appears in main.sh: line 2: ./a.out: No such file or directory

Substring Evaluation

Testing if the previous output contains the string All tests passed: False

Initial Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

LLM Generation

Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

Output

Certainly! Here's the equivalent function in C: 

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#define PH 16

int** rref(int **matrix, int rows, int cols, int graphlen) {
    int **used_for_row = (int **)malloc(rows * sizeof(int *));
    for (int i = 0; i < rows; ++i) {
        used_for_row[i] = (int *)malloc(sizeof(int));
        used_for_row[i][0] = i;
    }

    int extra = 0;
    int col = 0;

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; --i) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int *temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int *temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;
        }

        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        for (int j = 0; j < cols; ++j) {
            matrix[col][j] *= pivot;
            matrix[col][j] %= PH;
        }

        for (int i = 0; i < rows; ++i) {
            if (i == col) continue;

            int nonzero = 0;
            for (int j = 0; j < cols; ++j) {
                if (matrix[i][j] != 0) {
                    nonzero = 1;
                    break;
                }
            }
            if (!nonzero) continue;

            // Union of sets
            int *new_set = (int *)malloc((2 * sizeof(int)));
            int k = 0;
            for (int j = 0; j < 1; ++j) {
                new_set[k++] = used_for_row[i][j];
            }
            for (int j = 0; j < 1; ++j) {
                new_set[k++] = used_for_row[col][j];
            }
            used_for_row[i] = new_set;

            if (col < graphlen) {
                for (int j = 0; j < cols; ++j) {
                    matrix[i][j] -= matrix[col][j] * matrix[i][col + extra];
                    matrix[i][j] %= PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; ++j) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    return used_for_row;
}

// Helper function to print the matrix
void printMatrix(int **matrix, int rows, int cols) {
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int main() {
    int rows = 3, cols = 4, graphlen = 2;

    // Example usage
    int **matrix = (int **)malloc(rows * sizeof(int *));
    for (int i = 0; i < rows; ++i) {
        matrix[i] = (int *)malloc(cols * sizeof(int));
    }

    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3; matrix[0][3] = 4;
    matrix[1][0] = 5; matrix[1][1] = 6; matrix[1][2] = 7; matrix[1][3] = 8;
    matrix[2][0] = 9; matrix[2][1] = 10; matrix[2][2] = 11; matrix[2][3] = 12;

    int **used_for_row = rref(matrix, rows, cols, graphlen);

    printf("Matrix after RREF:\n");
    printMatrix(matrix, rows, cols);

    printf("Used for row:\n");
    for (int i = 0; i < rows; ++i) {
        printf("%d\n", used_for_row[i][0]);
    }

    // Free allocated memory
    for (int i = 0; i < rows; ++i) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}
This implementation assumes the input matrix is correctly allocated and formatted. The `graphlen` parameter is used to check the pivot's conditions. The function returns a dynamically allocated 2D array `used_for_row`, which tracks the rows where the pivot was used. Please note that this code uses dynamic memory allocation for the `used_for_row` array and assumes the input matrix is dynamically allocated. You might need to adjust memory management according to your specific requirements.

Extract Code

I extracted the following code from that output: 

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#define PH 16

int** rref(int **matrix, int rows, int cols, int graphlen) {
    int **used_for_row = (int **)malloc(rows * sizeof(int *));
    for (int i = 0; i < rows; ++i) {
        used_for_row[i] = (int *)malloc(sizeof(int));
        used_for_row[i][0] = i;
    }

    int extra = 0;
    int col = 0;

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; --i) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int *temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int *temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;
        }

        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        for (int j = 0; j < cols; ++j) {
            matrix[col][j] *= pivot;
            matrix[col][j] %= PH;
        }

        for (int i = 0; i < rows; ++i) {
            if (i == col) continue;

            int nonzero = 0;
            for (int j = 0; j < cols; ++j) {
                if (matrix[i][j] != 0) {
                    nonzero = 1;
                    break;
                }
            }
            if (!nonzero) continue;

            // Union of sets
            int *new_set = (int *)malloc((2 * sizeof(int)));
            int k = 0;
            for (int j = 0; j < 1; ++j) {
                new_set[k++] = used_for_row[i][j];
            }
            for (int j = 0; j < 1; ++j) {
                new_set[k++] = used_for_row[col][j];
            }
            used_for_row[i] = new_set;

            if (col < graphlen) {
                for (int j = 0; j < cols; ++j) {
                    matrix[i][j] -= matrix[col][j] * matrix[i][col + extra];
                    matrix[i][j] %= PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; ++j) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    return used_for_row;
}

// Helper function to print the matrix
void printMatrix(int **matrix, int rows, int cols) {
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int main() {
    int rows = 3, cols = 4, graphlen = 2;

    // Example usage
    int **matrix = (int **)malloc(rows * sizeof(int *));
    for (int i = 0; i < rows; ++i) {
        matrix[i] = (int *)malloc(cols * sizeof(int));
    }

    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3; matrix[0][3] = 4;
    matrix[1][0] = 5; matrix[1][1] = 6; matrix[1][2] = 7; matrix[1][3] = 8;
    matrix[2][0] = 9; matrix[2][1] = 10; matrix[2][2] = 11; matrix[2][3] = 12;

    int **used_for_row = rref(matrix, rows, cols, graphlen);

    printf("Matrix after RREF:\n");
    printMatrix(matrix, rows, cols);

    printf("Used for row:\n");
    for (int i = 0; i < rows; ++i) {
        printf("%d\n", used_for_row[i][0]);
    }

    // Free allocated memory
    for (int i = 0; i < rows; ++i) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#define PH 16

int** rref(int **matrix, int rows, int cols, int graphlen) {
    int **used_for_row = (int **)malloc(rows * sizeof(int *));
    for (int i = 0; i < rows; ++i) {
        used_for_row[i] = (int *)malloc(sizeof(int));
        used_for_row[i][0] = i;
    }

    int extra = 0;
    int col = 0;

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; --i) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int *temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int *temp_set = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_set;
        }

        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        for (int j = 0; j < cols; ++j) {
            matrix[col][j] *= pivot;
            matrix[col][j] %= PH;
        }

        for (int i = 0; i < rows; ++i) {
            if (i == col) continue;

            int nonzero = 0;
            for (int j = 0; j < cols; ++j) {
                if (matrix[i][j] != 0) {
                    nonzero = 1;
                    break;
                }
            }
            if (!nonzero) continue;

            // Union of sets
            int *new_set = (int *)malloc((2 * sizeof(int)));
            int k = 0;
            for (int j = 0; j < 1; ++j) {
                new_set[k++] = used_for_row[i][j];
            }
            for (int j = 0; j < 1; ++j) {
                new_set[k++] = used_for_row[col][j];
            }
            used_for_row[i] = new_set;

            if (col < graphlen) {
                for (int j = 0; j < cols; ++j) {
                    matrix[i][j] -= matrix[col][j] * matrix[i][col + extra];
                    matrix[i][j] %= PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; ++j) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    return used_for_row;
}

// Helper function to print the matrix
void printMatrix(int **matrix, int rows, int cols) {
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int __delete_this__main() {
    int rows = 3, cols = 4, graphlen = 2;

    // Example usage
    int **matrix = (int **)malloc(rows * sizeof(int *));
    for (int i = 0; i < rows; ++i) {
        matrix[i] = (int *)malloc(cols * sizeof(int));
    }

    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3; matrix[0][3] = 4;
    matrix[1][0] = 5; matrix[1][1] = 6; matrix[1][2] = 7; matrix[1][3] = 8;
    matrix[2][0] = 9; matrix[2][1] = 10; matrix[2][2] = 11; matrix[2][3] = 12;

    int **used_for_row = rref(matrix, rows, cols, graphlen);

    printf("Matrix after RREF:\n");
    printMatrix(matrix, rows, cols);

    printf("Used for row:\n");
    for (int i = 0; i < rows; ++i) {
        printf("%d\n", used_for_row[i][0]);
    }

    // Free allocated memory
    for (int i = 0; i < rows; ++i) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}



#include<stdio.h>
#include<stdlib.h>

int main() {

int arr0[] = {1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr1[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr2[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr3[] = {0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr4[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr5[] = {0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr6[] = {0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0};
int arr7[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, -30};
int arr8[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr9[] = {0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, -20};
int arr10[] = {1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr11[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr12[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr13[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -14};
int arr14[] = {0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr15[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, -30};
int arr16[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr17[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr18[] = {0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr19[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr20[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr21[] = {0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr22[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, -20};
int arr23[] = {0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr24[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr25[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr26[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr27[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr28[] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr29[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr30[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr31[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr32[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, -10};
int arr33[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr34[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr35[] = {0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -9};
int arr36[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, -20};
int arr37[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, -40};
int arr38[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int* arr[] = {arr0, arr1, arr2, arr3, arr4, arr5, arr6, arr7, arr8, arr9, arr10, arr11, arr12, arr13, arr14, arr15, arr16, arr17, arr18, arr19, arr20, arr21, arr22, arr23, arr24, arr25, arr26, arr27, arr28, arr29, arr30, arr31, arr32, arr33, arr34, arr35, arr36, arr37, arr38};
int** got = rref(arr, 39, 49, 37);


int answer = got[3][0]+got[3][1]+got[3][2]+got[3][3]+got[3][4]+got[3][5]+got[3][6];
int expected = 146;
if (answer != expected) {
    printf("Wrong answer; got %d instead of %d.\n", answer, expected);
    exit(1);
}
printf("All tests passed\n");
}
And got the output: Wrong answer; got 73 instead of 146.

Substring Evaluation

Testing if the previous output contains the string All tests passed: False

Initial Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

LLM Generation

Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

Output

Sure, here is the equivalent function in C: 

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0, col = 0;
    int* pivots = (int*)malloc(cols * sizeof(int));
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(sizeof(int));
        used_for_row[i][0] = i;
    }

    // Apply modulo PH to the matrix
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col] != 0) {
                    all_zero = 0;
                    break;
                }
            }

            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int* tempUsed = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = tempUsed;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            if (abs(pivot) != 1 && abs(pivot) != PH - 1) {
                printf("Assertion failed\n");
                exit(1);
            }
        } else {
            if (abs(pivot) != 2 && abs(pivot) != PH - 2) {
                printf("Assertion failed\n");
                exit(1);
            }
            pivot /= 2;
        }

        for (int j = 0; j < cols; j++) {
            matrix[col][j] *= pivot;
            matrix[col][j] %= PH;
        }

        for (int i = 0; i < rows; i++) {
            if (i == col) continue;

            used_for_row[i] = (int*)realloc(used_for_row[i], sizeof(int) * (sizeof(used_for_row[i]) / sizeof(int) + 1));
            int k = 0;
            while (used_for_row[i][k] != '\0') {
                k++;
            }
            used_for_row[i][k] = used_for_row[col][0];

            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[i][j] -= (matrix[col][j] * matrix[i][col + extra]) % PH;
                    matrix[i][j] %= PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    return used_for_row;
}

// Helper function to print the matrix
void printMatrix(int** matrix, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int main() {
    int rows = 3, cols = 4, graphlen = 2;
    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    // Example matrix
    int data[3][4] = {
        {2, 4, 6, 8},
        {1, 3, 5, 7},
        {9, 7, 5, 3}
    };

    // Copy data to matrix
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] = data[i][j];
        }
    }

    printf("Original Matrix:\n");
    printMatrix(matrix, rows, cols);

    int** used_for_row = rref(matrix, rows, cols, graphlen);

    printf("RREF Matrix:\n");
    printMatrix(matrix, rows, cols);

    printf("Used for Row:\n");
    for (int i = 0; i < rows; i++) {
        int j = 0;
        while (used_for_row[i][j] != '\0') {
            printf("%d ", used_for_row[i][j]);
            j++;
        }
        printf("\n");
    }

    // Free allocated memory
    for (int i = 0; i < rows; i++) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}
This code assumes that `graphlen` is a valid parameter provided during function call and that the input matrix is correctly formatted as a 2D array. It follows the logic of the Python function, using C constructs and functions. Note that error checking and memory management are critical when working with dynamic memory allocation in C. The code provided includes basic memory allocation and deallocation, but it might need further refinement depending on specific use cases and requirements.

Extract Code

I extracted the following code from that output: 

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0, col = 0;
    int* pivots = (int*)malloc(cols * sizeof(int));
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(sizeof(int));
        used_for_row[i][0] = i;
    }

    // Apply modulo PH to the matrix
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col] != 0) {
                    all_zero = 0;
                    break;
                }
            }

            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int* tempUsed = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = tempUsed;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            if (abs(pivot) != 1 && abs(pivot) != PH - 1) {
                printf("Assertion failed\n");
                exit(1);
            }
        } else {
            if (abs(pivot) != 2 && abs(pivot) != PH - 2) {
                printf("Assertion failed\n");
                exit(1);
            }
            pivot /= 2;
        }

        for (int j = 0; j < cols; j++) {
            matrix[col][j] *= pivot;
            matrix[col][j] %= PH;
        }

        for (int i = 0; i < rows; i++) {
            if (i == col) continue;

            used_for_row[i] = (int*)realloc(used_for_row[i], sizeof(int) * (sizeof(used_for_row[i]) / sizeof(int) + 1));
            int k = 0;
            while (used_for_row[i][k] != '\0') {
                k++;
            }
            used_for_row[i][k] = used_for_row[col][0];

            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[i][j] -= (matrix[col][j] * matrix[i][col + extra]) % PH;
                    matrix[i][j] %= PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    return used_for_row;
}

// Helper function to print the matrix
void printMatrix(int** matrix, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int main() {
    int rows = 3, cols = 4, graphlen = 2;
    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    // Example matrix
    int data[3][4] = {
        {2, 4, 6, 8},
        {1, 3, 5, 7},
        {9, 7, 5, 3}
    };

    // Copy data to matrix
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] = data[i][j];
        }
    }

    printf("Original Matrix:\n");
    printMatrix(matrix, rows, cols);

    int** used_for_row = rref(matrix, rows, cols, graphlen);

    printf("RREF Matrix:\n");
    printMatrix(matrix, rows, cols);

    printf("Used for Row:\n");
    for (int i = 0; i < rows; i++) {
        int j = 0;
        while (used_for_row[i][j] != '\0') {
            printf("%d ", used_for_row[i][j]);
            j++;
        }
        printf("\n");
    }

    // Free allocated memory
    for (int i = 0; i < rows; i++) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0, col = 0;
    int* pivots = (int*)malloc(cols * sizeof(int));
    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        used_for_row[i] = (int*)malloc(sizeof(int));
        used_for_row[i][0] = i;
    }

    // Apply modulo PH to the matrix
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; i++) {
                if (matrix[i][col] != 0) {
                    all_zero = 0;
                    break;
                }
            }

            if (all_zero) {
                extra++;
                continue;
            }

            int other = -1;
            for (int i = rows - 1; i >= 0; i--) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                    break;
                }
            }

            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int* tempUsed = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = tempUsed;
        }

        pivots[col] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            if (abs(pivot) != 1 && abs(pivot) != PH - 1) {
                printf("Assertion failed\n");
                exit(1);
            }
        } else {
            if (abs(pivot) != 2 && abs(pivot) != PH - 2) {
                printf("Assertion failed\n");
                exit(1);
            }
            pivot /= 2;
        }

        for (int j = 0; j < cols; j++) {
            matrix[col][j] *= pivot;
            matrix[col][j] %= PH;
        }

        for (int i = 0; i < rows; i++) {
            if (i == col) continue;

            used_for_row[i] = (int*)realloc(used_for_row[i], sizeof(int) * (sizeof(used_for_row[i]) / sizeof(int) + 1));
            int k = 0;
            while (used_for_row[i][k] != '\0') {
                k++;
            }
            used_for_row[i][k] = used_for_row[col][0];

            if (col < graphlen) {
                for (int j = 0; j < cols; j++) {
                    matrix[i][j] -= (matrix[col][j] * matrix[i][col + extra]) % PH;
                    matrix[i][j] %= PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; j++) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] %= PH;
        }
    }

    return used_for_row;
}

// Helper function to print the matrix
void printMatrix(int** matrix, int rows, int cols) {
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", matrix[i][j]);
        }
        printf("\n");
    }
}

int __delete_this__main() {
    int rows = 3, cols = 4, graphlen = 2;
    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; i++) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    // Example matrix
    int data[3][4] = {
        {2, 4, 6, 8},
        {1, 3, 5, 7},
        {9, 7, 5, 3}
    };

    // Copy data to matrix
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            matrix[i][j] = data[i][j];
        }
    }

    printf("Original Matrix:\n");
    printMatrix(matrix, rows, cols);

    int** used_for_row = rref(matrix, rows, cols, graphlen);

    printf("RREF Matrix:\n");
    printMatrix(matrix, rows, cols);

    printf("Used for Row:\n");
    for (int i = 0; i < rows; i++) {
        int j = 0;
        while (used_for_row[i][j] != '\0') {
            printf("%d ", used_for_row[i][j]);
            j++;
        }
        printf("\n");
    }

    // Free allocated memory
    for (int i = 0; i < rows; i++) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}



#include<stdio.h>
#include<stdlib.h>

int main() {

int arr0[] = {1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr1[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr2[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr3[] = {0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr4[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr5[] = {0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr6[] = {0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0};
int arr7[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, -30};
int arr8[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr9[] = {0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, -20};
int arr10[] = {1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr11[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr12[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr13[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -14};
int arr14[] = {0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr15[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, -30};
int arr16[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr17[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr18[] = {0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr19[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr20[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr21[] = {0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr22[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, -20};
int arr23[] = {0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr24[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr25[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr26[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr27[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr28[] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr29[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr30[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr31[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr32[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, -10};
int arr33[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr34[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr35[] = {0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -9};
int arr36[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, -20};
int arr37[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, -40};
int arr38[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int* arr[] = {arr0, arr1, arr2, arr3, arr4, arr5, arr6, arr7, arr8, arr9, arr10, arr11, arr12, arr13, arr14, arr15, arr16, arr17, arr18, arr19, arr20, arr21, arr22, arr23, arr24, arr25, arr26, arr27, arr28, arr29, arr30, arr31, arr32, arr33, arr34, arr35, arr36, arr37, arr38};
int** got = rref(arr, 39, 49, 37);


int answer = got[3][0]+got[3][1]+got[3][2]+got[3][3]+got[3][4]+got[3][5]+got[3][6];
int expected = 146;
if (answer != expected) {
    printf("Wrong answer; got %d instead of %d.\n", answer, expected);
    exit(1);
}
printf("All tests passed\n");
}
And got the output: realloc(): invalid old size main.sh: line 2: 16 Aborted (core dumped) ./a.out

Substring Evaluation

Testing if the previous output contains the string All tests passed: False

Initial Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

LLM Generation

Query

Rewrite this function in C. You can assume that the input is a 2d matrix correctly formatted. Call it rref(int** matrix, int rows, int cols, int graphlen) where the size is matrix[rows][cols]. Return an int** of used_for_row. def rref(matrix, graphlen): PH = 16 extra = 0 col = 0 pivots = [] used_for_row = [set([i]) for i in range(matrix.shape[0])] matrix = matrix%PH while col+extra < matrix.shape[1]-1 and col < matrix.shape[0]: if matrix[col,col+extra] == 0: if np.all(matrix[:,col] == 0): extra += 1 continue other = np.argwhere(matrix[:,col+extra] != 0).flatten()[-1] if other < col: extra += 1 continue matrix[col], matrix[other] = list(matrix[other]), list(matrix[col]) used_for_row[col], used_for_row[other] = used_for_row[other], used_for_row[col] pivots.append(col+extra) pivot = matrix[col,col+extra] if col+extra < graphlen: assert np.abs(pivot) == 1 or np.abs(pivot) == PH-1 else: assert np.abs(pivot) == 2 or np.abs(pivot) == PH-2 pivot //= 2 matrix[col] *= pivot matrix[col] %= PH others = np.argwhere(matrix[:,col+extra]).flatten() for i in others: if i == col: continue used_for_row[i] |= used_for_row[col] if col < graphlen: matrix[i] -= matrix[col]*matrix[i,col+extra] else: while matrix[i,col+extra] != 0: matrix[i] = (matrix[i]-matrix[col])%PH matrix[i] %= PH col += 1 matrix = np.array(matrix)%PH return [sorted(x) for x in used_for_row]

Output

Sure, here's the equivalent C function for the provided Python function. This function will convert the input matrix to its reduced row echelon form (RREF) and return an array of sets representing the `used_for_row`. Note that we cannot directly use sets in C, so we will use a 2D array to simulate the sets. 

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int *pivots = (int*)malloc(rows * sizeof(int));
    int pivot_count = 0;

    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; ++i) {
        used_for_row[i] = (int*)malloc(rows * sizeof(int));
        for (int j = 0; j < rows; ++j) {
            used_for_row[i][j] = (i == j) ? 1 : 0;
        }
    }

    // Modulo operation
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }
            int other = -1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                }
            }
            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int* temp_row = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_row;
        }

        pivots[pivot_count++] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        // Normalize the pivot row
        for (int j = 0; j < cols; ++j) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        for (int i = 0; i < rows; ++i) {
            if (i == col) continue;
            for (int j = 0; j < rows; ++j) {
                used_for_row[i][j] |= used_for_row[col][j];
            }
            if (col < graphlen) {
                int factor = matrix[i][col + extra];
                for (int j = 0; j < cols; ++j) {
                    matrix[i][j] = (matrix[i][j] - matrix[col][j] * factor) % PH;
                    if (matrix[i][j] < 0) matrix[i][j] += PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; ++j) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                        if (matrix[i][j] < 0) matrix[i][j] += PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    free(pivots);
    return used_for_row;
}

// Example usage
int main() {
    int rows = 3, cols = 4, graphlen = 3;
    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; ++i) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    // Initialize the matrix
    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3; matrix[0][3] = 4;
    matrix[1][0] = 2; matrix[1][1] = 3; matrix[1][2] = 4; matrix[1][3] = 5;
    matrix[2][0] = 3; matrix[2][1] = 4; matrix[2][2] = 5; matrix[2][3] = 6;

    int** used_for_row = rref(matrix, rows, cols, graphlen);

    // Print the used_for_row matrix
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < rows; ++j) {
            printf("%d ", used_for_row[i][j]);
        }
        printf("\n");
    }

    // Free allocated memory
    for (int i = 0; i < rows; ++i) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}
In this implementation, `used_for_row` is represented as a 2D array of integers where each row denotes the set of original rows used to obtain the corresponding row in the RREF matrix. The usage of assertions and matrix operations has been translated to corresponding C code, including handling of the modulo operation. Note that error checking and edge cases should be handled appropriately in a production environment.

Extract Code

I extracted the following code from that output: 

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int *pivots = (int*)malloc(rows * sizeof(int));
    int pivot_count = 0;

    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; ++i) {
        used_for_row[i] = (int*)malloc(rows * sizeof(int));
        for (int j = 0; j < rows; ++j) {
            used_for_row[i][j] = (i == j) ? 1 : 0;
        }
    }

    // Modulo operation
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }
            int other = -1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                }
            }
            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int* temp_row = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_row;
        }

        pivots[pivot_count++] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        // Normalize the pivot row
        for (int j = 0; j < cols; ++j) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        for (int i = 0; i < rows; ++i) {
            if (i == col) continue;
            for (int j = 0; j < rows; ++j) {
                used_for_row[i][j] |= used_for_row[col][j];
            }
            if (col < graphlen) {
                int factor = matrix[i][col + extra];
                for (int j = 0; j < cols; ++j) {
                    matrix[i][j] = (matrix[i][j] - matrix[col][j] * factor) % PH;
                    if (matrix[i][j] < 0) matrix[i][j] += PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; ++j) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                        if (matrix[i][j] < 0) matrix[i][j] += PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    free(pivots);
    return used_for_row;
}

// Example usage
int main() {
    int rows = 3, cols = 4, graphlen = 3;
    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; ++i) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    // Initialize the matrix
    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3; matrix[0][3] = 4;
    matrix[1][0] = 2; matrix[1][1] = 3; matrix[1][2] = 4; matrix[1][3] = 5;
    matrix[2][0] = 3; matrix[2][1] = 4; matrix[2][2] = 5; matrix[2][3] = 6;

    int** used_for_row = rref(matrix, rows, cols, graphlen);

    // Print the used_for_row matrix
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < rows; ++j) {
            printf("%d ", used_for_row[i][j]);
        }
        printf("\n");
    }

    // Free allocated memory
    for (int i = 0; i < rows; ++i) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}

Run Code Interpreter

Running the following program: 

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#define PH 16

int** rref(int** matrix, int rows, int cols, int graphlen) {
    int extra = 0;
    int col = 0;
    int *pivots = (int*)malloc(rows * sizeof(int));
    int pivot_count = 0;

    int** used_for_row = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; ++i) {
        used_for_row[i] = (int*)malloc(rows * sizeof(int));
        for (int j = 0; j < rows; ++j) {
            used_for_row[i][j] = (i == j) ? 1 : 0;
        }
    }

    // Modulo operation
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    while (col + extra < cols - 1 && col < rows) {
        if (matrix[col][col + extra] == 0) {
            int all_zero = 1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col + extra] != 0) {
                    all_zero = 0;
                    break;
                }
            }
            if (all_zero) {
                extra++;
                continue;
            }
            int other = -1;
            for (int i = 0; i < rows; ++i) {
                if (matrix[i][col + extra] != 0) {
                    other = i;
                }
            }
            if (other < col) {
                extra++;
                continue;
            }

            // Swap rows
            int* temp = matrix[col];
            matrix[col] = matrix[other];
            matrix[other] = temp;

            // Swap used_for_row
            int* temp_row = used_for_row[col];
            used_for_row[col] = used_for_row[other];
            used_for_row[other] = temp_row;
        }

        pivots[pivot_count++] = col + extra;
        int pivot = matrix[col][col + extra];
        if (col + extra < graphlen) {
            assert(abs(pivot) == 1 || abs(pivot) == PH - 1);
        } else {
            assert(abs(pivot) == 2 || abs(pivot) == PH - 2);
            pivot /= 2;
        }

        // Normalize the pivot row
        for (int j = 0; j < cols; ++j) {
            matrix[col][j] = (matrix[col][j] * pivot) % PH;
        }

        for (int i = 0; i < rows; ++i) {
            if (i == col) continue;
            for (int j = 0; j < rows; ++j) {
                used_for_row[i][j] |= used_for_row[col][j];
            }
            if (col < graphlen) {
                int factor = matrix[i][col + extra];
                for (int j = 0; j < cols; ++j) {
                    matrix[i][j] = (matrix[i][j] - matrix[col][j] * factor) % PH;
                    if (matrix[i][j] < 0) matrix[i][j] += PH;
                }
            } else {
                while (matrix[i][col + extra] != 0) {
                    for (int j = 0; j < cols; ++j) {
                        matrix[i][j] = (matrix[i][j] - matrix[col][j]) % PH;
                        if (matrix[i][j] < 0) matrix[i][j] += PH;
                    }
                }
            }
        }

        col++;
    }

    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            matrix[i][j] %= PH;
        }
    }

    free(pivots);
    return used_for_row;
}

// Example usage
int __delete_this__main() {
    int rows = 3, cols = 4, graphlen = 3;
    int** matrix = (int**)malloc(rows * sizeof(int*));
    for (int i = 0; i < rows; ++i) {
        matrix[i] = (int*)malloc(cols * sizeof(int));
    }

    // Initialize the matrix
    matrix[0][0] = 1; matrix[0][1] = 2; matrix[0][2] = 3; matrix[0][3] = 4;
    matrix[1][0] = 2; matrix[1][1] = 3; matrix[1][2] = 4; matrix[1][3] = 5;
    matrix[2][0] = 3; matrix[2][1] = 4; matrix[2][2] = 5; matrix[2][3] = 6;

    int** used_for_row = rref(matrix, rows, cols, graphlen);

    // Print the used_for_row matrix
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < rows; ++j) {
            printf("%d ", used_for_row[i][j]);
        }
        printf("\n");
    }

    // Free allocated memory
    for (int i = 0; i < rows; ++i) {
        free(matrix[i]);
        free(used_for_row[i]);
    }
    free(matrix);
    free(used_for_row);

    return 0;
}



#include<stdio.h>
#include<stdlib.h>

int main() {

int arr0[] = {1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr1[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr2[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr3[] = {0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0, -20};
int arr4[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr5[] = {0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr6[] = {0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 0, 0};
int arr7[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, -30};
int arr8[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr9[] = {0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, -20};
int arr10[] = {1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
int arr11[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr12[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr13[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -14};
int arr14[] = {0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr15[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, -30};
int arr16[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr17[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr18[] = {0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr19[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr20[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr21[] = {0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr22[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, -20};
int arr23[] = {0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -10};
int arr24[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr25[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr26[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr27[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr28[] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr29[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr30[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int arr31[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr32[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, 0, -10};
int arr33[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -13};
int arr34[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -11};
int arr35[] = {0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -9};
int arr36[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 0, -20};
int arr37[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, -40};
int arr38[] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
int* arr[] = {arr0, arr1, arr2, arr3, arr4, arr5, arr6, arr7, arr8, arr9, arr10, arr11, arr12, arr13, arr14, arr15, arr16, arr17, arr18, arr19, arr20, arr21, arr22, arr23, arr24, arr25, arr26, arr27, arr28, arr29, arr30, arr31, arr32, arr33, arr34, arr35, arr36, arr37, arr38};
int** got = rref(arr, 39, 49, 37);


int answer = got[3][0]+got[3][1]+got[3][2]+got[3][3]+got[3][4]+got[3][5]+got[3][6];
int expected = 146;
if (answer != expected) {
    printf("Wrong answer; got %d instead of %d.\n", answer, expected);
    exit(1);
}
printf("All tests passed\n");
}
And got the output: Wrong answer; got 7 instead of 146.

Substring Evaluation

Testing if the previous output contains the string All tests passed: False