A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
### Plan 1. **Matrix Representation**: - Use an `unsigned long` (64 bits) to represent an 8x8 matrix. Each bit will represent a cell in the matrix (0 for `0`, 1 for `1`). - The 8x8 matrix will be represented as two rows of 32 bits each. 2. **Function to Check 'Unholy'**: - Create a function `is_unholy(unsigned long matrix)` that checks if the given matrix contains isolated `1`s. This function will: - Shift the bits and use masking to check the four cardinal directions (up, down, left, right) for each `1` in the matrix. 3. **Dynamic Programming to Count Unholy Matrices**: - Use recursion to evaluate each row of the matrix, generating all possible combinations for the next two rows (total of `2^16` combinations for two rows). - Store results in an array to avoid recalculating previously computed results for the same state. 4. **Main Function**: - Initialize the total count of unholy matrices. - Call the recursive function starting with the first row. - Print the total count. ### C Implementation
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 | #include <stdio.h> #include <stdint.h> #define MATRIX_SIZE 8 #define FULL_MASK 0xFF // 8 bits for a row // Function to check if a given matrix is unholy int is_unholy(unsigned long matrix) { for (int i = 0; i < MATRIX_SIZE; i++) { for (int j = 0; j < MATRIX_SIZE; j++) { // Check if the current cell is a '1' if ((matrix & (1UL << (i * MATRIX_SIZE + j))) != 0) { // Check up if (i > 0 && (matrix & (1UL << ((i - 1) * MATRIX_SIZE + j))) != 0) continue; // Check down if (i < MATRIX_SIZE - 1 && (matrix & (1UL << ((i + 1) * MATRIX_SIZE + j))) != 0) continue; // Check left if (j > 0 && (matrix & (1UL << (i * MATRIX_SIZE + (j - 1)))) != 0) continue; // Check right if (j < MATRIX_SIZE - 1 && (matrix & (1UL << (i * MATRIX_SIZE + (j + 1)))) != 0) continue; // If no adjacent '1's found, it is isolated return 0; } } } return 1; // No isolated '1's found, the matrix is unholy } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_matrix) { if (row >= MATRIX_SIZE) { return is_unholy(prev_matrix) ? 1 : 0; } unsigned long total_count = 0; // Iterate through every combination of the next two rows (2^16 possibilities) for (unsigned long next_rows = 0; next_rows < (1UL << (MATRIX_SIZE * 2)); next_rows++) { unsigned long current_matrix = prev_matrix | (next_rows & ((1UL << (MATRIX_SIZE * 2)) - 1)); total_count += count_unholy_matrices(row + 2, current_matrix); } return total_count; } int main() { unsigned long total_unholy_matrices = 0; // Start the recursive counting from row 0 with an empty previous matrix total_unholy_matrices = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy_matrices); return 0; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 | #include <stdio.h> #include <stdint.h> #define MATRIX_SIZE 8 #define FULL_MASK 0xFF // 8 bits for a row // Function to check if a given matrix is unholy int is_unholy(unsigned long matrix) { for (int i = 0; i < MATRIX_SIZE; i++) { for (int j = 0; j < MATRIX_SIZE; j++) { // Check if the current cell is a '1' if ((matrix & (1UL << (i * MATRIX_SIZE + j))) != 0) { // Check up if (i > 0 && (matrix & (1UL << ((i - 1) * MATRIX_SIZE + j))) != 0) continue; // Check down if (i < MATRIX_SIZE - 1 && (matrix & (1UL << ((i + 1) * MATRIX_SIZE + j))) != 0) continue; // Check left if (j > 0 && (matrix & (1UL << (i * MATRIX_SIZE + (j - 1)))) != 0) continue; // Check right if (j < MATRIX_SIZE - 1 && (matrix & (1UL << (i * MATRIX_SIZE + (j + 1)))) != 0) continue; // If no adjacent '1's found, it is isolated return 0; } } } return 1; // No isolated '1's found, the matrix is unholy } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_matrix) { if (row >= MATRIX_SIZE) { return is_unholy(prev_matrix) ? 1 : 0; } unsigned long total_count = 0; // Iterate through every combination of the next two rows (2^16 possibilities) for (unsigned long next_rows = 0; next_rows < (1UL << (MATRIX_SIZE * 2)); next_rows++) { unsigned long current_matrix = prev_matrix | (next_rows & ((1UL << (MATRIX_SIZE * 2)) - 1)); total_count += count_unholy_matrices(row + 2, current_matrix); } return total_count; } int main() { unsigned long total_unholy_matrices = 0; // Start the recursive counting from row 0 with an empty previous matrix total_unholy_matrices = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy_matrices); return 0; } |
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 | #include <stdio.h> #include <stdint.h> #define MATRIX_SIZE 8 #define FULL_MASK 0xFF // 8 bits for a row // Function to check if a given matrix is unholy int is_unholy(unsigned long matrix) { for (int i = 0; i < MATRIX_SIZE; i++) { for (int j = 0; j < MATRIX_SIZE; j++) { // Check if the current cell is a '1' if ((matrix & (1UL << (i * MATRIX_SIZE + j))) != 0) { // Check up if (i > 0 && (matrix & (1UL << ((i - 1) * MATRIX_SIZE + j))) != 0) continue; // Check down if (i < MATRIX_SIZE - 1 && (matrix & (1UL << ((i + 1) * MATRIX_SIZE + j))) != 0) continue; // Check left if (j > 0 && (matrix & (1UL << (i * MATRIX_SIZE + (j - 1)))) != 0) continue; // Check right if (j < MATRIX_SIZE - 1 && (matrix & (1UL << (i * MATRIX_SIZE + (j + 1)))) != 0) continue; // If no adjacent '1's found, it is isolated return 0; } } } return 1; // No isolated '1's found, the matrix is unholy } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_matrix) { if (row >= MATRIX_SIZE) { return is_unholy(prev_matrix) ? 1 : 0; } unsigned long total_count = 0; // Iterate through every combination of the next two rows (2^16 possibilities) for (unsigned long next_rows = 0; next_rows < (1UL << (MATRIX_SIZE * 2)); next_rows++) { unsigned long current_matrix = prev_matrix | (next_rows & ((1UL << (MATRIX_SIZE * 2)) - 1)); total_count += count_unholy_matrices(row + 2, current_matrix); } return total_count; } int main() { unsigned long total_unholy_matrices = 0; // Start the recursive counting from row 0 with an empty previous matrix total_unholy_matrices = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy_matrices); return 0; } |
Timeout: function took too long to complete
Testing if the previous output contains the string 1121231537486377866
: False
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
To solve the problem of counting the total number of "unholy" 8x8 binary matrices using bit arithmetic, we will implement a C program that utilizes dynamic programming combined with recursion. Below is a detailed plan followed by the actual implementation. ### Plan: 1. **Matrix Representation**: - Use an `unsigned long` (64 bits) to represent an 8x8 binary matrix. Each bit will represent a cell in the matrix (0 for empty, 1 for filled). 2. **Define the Unholy Condition**: - A matrix is unholy if there are no isolated 1s. A 1 is considered isolated if there are no other 1s in the left, right, up, or down cells. 3. **Function to Check Unholiness**: - Implement a function `is_unholy(unsigned long matrix)` that checks if the given matrix is unholy by using bit manipulation (shifts and masks). 4. **Count Unholy Matrices**: - Use a recursive function that iterates through the rows of the matrix. For each row, generate all possible combinations of 2^8 (0 to 255) representing the next row. - For each combination, check if the current and previous rows combined form an unholy matrix using `is_unholy`. 5. **Dynamic Programming Table**: - Implement a memoization technique to store already computed results for specific row combinations to avoid redundant calculations. 6. **Main Function**: - Call the recursive function starting from the first row with an initial empty state and accumulate the count of unholy matrices. ### C Implementation:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | #include <stdio.h> #include <stdlib.h> #define SIZE 8 #define MAX_ROW_COMBINATIONS 256 // 2^8 combinations for a row // Function to check if a matrix is unholy int is_unholy(unsigned long current_row, unsigned long prev_row) { unsigned long combined = current_row | (prev_row << SIZE); // Combine current and previous row // Check each bit in the combined matrix for isolation for (int i = 0; i < SIZE * SIZE; i++) { if ((combined & (1UL << i)) != 0) { // If there is a '1' at position i // Check the four cardinal directions int row = i / SIZE; int col = i % SIZE; // Check up if (row > 0 && (combined & (1UL << (i - SIZE))) != 0) return 1; // Check down if (row < SIZE - 1 && (combined & (1UL << (i + SIZE))) != 0) return 1; // Check left if (col > 0 && (combined & (1UL << (i - 1))) != 0) return 1; // Check right if (col < SIZE - 1 && (combined & (1UL << (i + 1))) != 0) return 1; } } return 0; // No isolated 1s found, matrix is unholy } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_row) { if (row == SIZE) return 1; // Reached the bottom of the matrix unsigned long count = 0; for (unsigned long current_row = 0; current_row < MAX_ROW_COMBINATIONS; current_row++) { // Check if the current row and the previous row combined are unholy if (!is_unholy(current_row, prev_row)) { count += count_unholy_matrices(row + 1, current_row); // Recurse for the next row } } return count; } int main() { unsigned long total_unholy_matrices = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy_matrices); return 0; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | #include <stdio.h> #include <stdlib.h> #define SIZE 8 #define MAX_ROW_COMBINATIONS 256 // 2^8 combinations for a row // Function to check if a matrix is unholy int is_unholy(unsigned long current_row, unsigned long prev_row) { unsigned long combined = current_row | (prev_row << SIZE); // Combine current and previous row // Check each bit in the combined matrix for isolation for (int i = 0; i < SIZE * SIZE; i++) { if ((combined & (1UL << i)) != 0) { // If there is a '1' at position i // Check the four cardinal directions int row = i / SIZE; int col = i % SIZE; // Check up if (row > 0 && (combined & (1UL << (i - SIZE))) != 0) return 1; // Check down if (row < SIZE - 1 && (combined & (1UL << (i + SIZE))) != 0) return 1; // Check left if (col > 0 && (combined & (1UL << (i - 1))) != 0) return 1; // Check right if (col < SIZE - 1 && (combined & (1UL << (i + 1))) != 0) return 1; } } return 0; // No isolated 1s found, matrix is unholy } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_row) { if (row == SIZE) return 1; // Reached the bottom of the matrix unsigned long count = 0; for (unsigned long current_row = 0; current_row < MAX_ROW_COMBINATIONS; current_row++) { // Check if the current row and the previous row combined are unholy if (!is_unholy(current_row, prev_row)) { count += count_unholy_matrices(row + 1, current_row); // Recurse for the next row } } return count; } int main() { unsigned long total_unholy_matrices = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy_matrices); return 0; } |
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | #include <stdio.h> #include <stdlib.h> #define SIZE 8 #define MAX_ROW_COMBINATIONS 256 // 2^8 combinations for a row // Function to check if a matrix is unholy int is_unholy(unsigned long current_row, unsigned long prev_row) { unsigned long combined = current_row | (prev_row << SIZE); // Combine current and previous row // Check each bit in the combined matrix for isolation for (int i = 0; i < SIZE * SIZE; i++) { if ((combined & (1UL << i)) != 0) { // If there is a '1' at position i // Check the four cardinal directions int row = i / SIZE; int col = i % SIZE; // Check up if (row > 0 && (combined & (1UL << (i - SIZE))) != 0) return 1; // Check down if (row < SIZE - 1 && (combined & (1UL << (i + SIZE))) != 0) return 1; // Check left if (col > 0 && (combined & (1UL << (i - 1))) != 0) return 1; // Check right if (col < SIZE - 1 && (combined & (1UL << (i + 1))) != 0) return 1; } } return 0; // No isolated 1s found, matrix is unholy } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_row) { if (row == SIZE) return 1; // Reached the bottom of the matrix unsigned long count = 0; for (unsigned long current_row = 0; current_row < MAX_ROW_COMBINATIONS; current_row++) { // Check if the current row and the previous row combined are unholy if (!is_unholy(current_row, prev_row)) { count += count_unholy_matrices(row + 1, current_row); // Recurse for the next row } } return count; } int main() { unsigned long total_unholy_matrices = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy_matrices); return 0; } |
Timeout: function took too long to complete
Testing if the previous output contains the string 1121231537486377866
: False
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
To tackle the problem of counting the total number of unholy 8x8 binary matrices, we can break down the solution into several clear steps. Below is a structured plan followed by the implementation in C. ### Plan 1. **Matrix Representation**: - Represent the 8x8 matrix using an `unsigned long long` (64 bits) to represent the entire matrix, where each bit corresponds to a cell in the matrix (0 for '0', 1 for '1'). 2. **Isolating Function**: - Implement a function `is_unholy` that checks if a given matrix (bitwise representation) is unholy by checking each '1' and ensuring it has at least one neighboring '1' in the cardinal directions (up, down, left, right). 3. **Dynamic Programming Approach**: - Use recursion to explore the number of rows, keeping track of the current configuration of the previous row. - For each recursion level, iterate over all possible configurations of the next two rows (2^16 configurations). 4. **Counting Unholy Matrices**: - Maintain a count of valid unholy configurations through the recursive function. 5. **Main Function**: - Call the recursive function starting from the first row and initialize the count. ### Implementation in C Here is the C implementation following the outlined plan:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | #include <stdio.h> #define SIZE 8 #define ROW_MASK 0xFF // Mask for a single row (8 bits) // Function to check if the matrix is unholy int is_unholy(unsigned long long matrix) { for (int i = 0; i < SIZE; i++) { unsigned long long row = (matrix >> (i * SIZE)) & ROW_MASK; for (int j = 0; j < SIZE; j++) { if ((row & (1ULL << j)) != 0) { // If there is a '1' at (i, j) // Check the four cardinal directions int up = (i > 0) ? ((matrix >> ((i - 1) * SIZE) & ROW_MASK) & (1ULL << j)) != 0 : 0; int down = (i < SIZE - 1) ? ((matrix >> ((i + 1) * SIZE) & ROW_MASK) & (1ULL << j)) != 0 : 0; int left = (j > 0) ? (row & (1ULL << (j - 1))) != 0 : 0; int right = (j < SIZE - 1) ? (row & (1ULL << (j + 1))) != 0 : 0; if (!up && !down && !left && !right) { return 0; // Found an isolated '1' } } } } return 1; // No isolated '1's found } // Recursive function to count unholy matrices unsigned long long count_unholy(unsigned long long previous_row, int current_row) { if (current_row == SIZE) { return is_unholy(previous_row) ? 1 : 0; } unsigned long long count = 0; // Iterate through all combinations of the current row (2^8) for (unsigned long long current_row_config = 0; current_row_config < (1 << SIZE); current_row_config++) { // Combine previous and current row to form the full matrix unsigned long long new_matrix = (previous_row & ~(ROW_MASK << (current_row * SIZE))) | (current_row_config << (current_row * SIZE)); count += count_unholy(new_matrix, current_row + 1); } return count; } int main() { unsigned long long total_unholy_matrices = count_unholy(0, 0); printf("Total number of unholy 8x8 matrices: %llu\n", total_unholy_matrices); return 0; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | #include <stdio.h> #define SIZE 8 #define ROW_MASK 0xFF // Mask for a single row (8 bits) // Function to check if the matrix is unholy int is_unholy(unsigned long long matrix) { for (int i = 0; i < SIZE; i++) { unsigned long long row = (matrix >> (i * SIZE)) & ROW_MASK; for (int j = 0; j < SIZE; j++) { if ((row & (1ULL << j)) != 0) { // If there is a '1' at (i, j) // Check the four cardinal directions int up = (i > 0) ? ((matrix >> ((i - 1) * SIZE) & ROW_MASK) & (1ULL << j)) != 0 : 0; int down = (i < SIZE - 1) ? ((matrix >> ((i + 1) * SIZE) & ROW_MASK) & (1ULL << j)) != 0 : 0; int left = (j > 0) ? (row & (1ULL << (j - 1))) != 0 : 0; int right = (j < SIZE - 1) ? (row & (1ULL << (j + 1))) != 0 : 0; if (!up && !down && !left && !right) { return 0; // Found an isolated '1' } } } } return 1; // No isolated '1's found } // Recursive function to count unholy matrices unsigned long long count_unholy(unsigned long long previous_row, int current_row) { if (current_row == SIZE) { return is_unholy(previous_row) ? 1 : 0; } unsigned long long count = 0; // Iterate through all combinations of the current row (2^8) for (unsigned long long current_row_config = 0; current_row_config < (1 << SIZE); current_row_config++) { // Combine previous and current row to form the full matrix unsigned long long new_matrix = (previous_row & ~(ROW_MASK << (current_row * SIZE))) | (current_row_config << (current_row * SIZE)); count += count_unholy(new_matrix, current_row + 1); } return count; } int main() { unsigned long long total_unholy_matrices = count_unholy(0, 0); printf("Total number of unholy 8x8 matrices: %llu\n", total_unholy_matrices); return 0; } |
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | #include <stdio.h> #define SIZE 8 #define ROW_MASK 0xFF // Mask for a single row (8 bits) // Function to check if the matrix is unholy int is_unholy(unsigned long long matrix) { for (int i = 0; i < SIZE; i++) { unsigned long long row = (matrix >> (i * SIZE)) & ROW_MASK; for (int j = 0; j < SIZE; j++) { if ((row & (1ULL << j)) != 0) { // If there is a '1' at (i, j) // Check the four cardinal directions int up = (i > 0) ? ((matrix >> ((i - 1) * SIZE) & ROW_MASK) & (1ULL << j)) != 0 : 0; int down = (i < SIZE - 1) ? ((matrix >> ((i + 1) * SIZE) & ROW_MASK) & (1ULL << j)) != 0 : 0; int left = (j > 0) ? (row & (1ULL << (j - 1))) != 0 : 0; int right = (j < SIZE - 1) ? (row & (1ULL << (j + 1))) != 0 : 0; if (!up && !down && !left && !right) { return 0; // Found an isolated '1' } } } } return 1; // No isolated '1's found } // Recursive function to count unholy matrices unsigned long long count_unholy(unsigned long long previous_row, int current_row) { if (current_row == SIZE) { return is_unholy(previous_row) ? 1 : 0; } unsigned long long count = 0; // Iterate through all combinations of the current row (2^8) for (unsigned long long current_row_config = 0; current_row_config < (1 << SIZE); current_row_config++) { // Combine previous and current row to form the full matrix unsigned long long new_matrix = (previous_row & ~(ROW_MASK << (current_row * SIZE))) | (current_row_config << (current_row * SIZE)); count += count_unholy(new_matrix, current_row + 1); } return count; } int main() { unsigned long long total_unholy_matrices = count_unholy(0, 0); printf("Total number of unholy 8x8 matrices: %llu\n", total_unholy_matrices); return 0; } |
Timeout: function took too long to complete
Testing if the previous output contains the string 1121231537486377866
: False
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
To solve the problem of counting unholy 8x8 binary matrices, we can break down the task into a series of steps. Below is a structured plan followed by a C implementation: ### Plan 1. **Matrix Representation:** - Use an `unsigned long` to represent each row of the 8x8 matrix, which allows us to handle bit manipulations effectively. - Each bit in the `unsigned long` corresponds to a column in the row, where `1` represents a filled cell and `0` represents an empty cell. 2. **Define the `is_unholy` Function:** - This function will take a row and its neighboring rows (above and below) as input. - It will check each bit in the current row to see if it is isolated. A bit is considered isolated if: - It is `1` and the bits directly above and below it (in the previous and next rows) are `0`. - The bits directly to the left and right are also `0` (unless it’s at the edge). 3. **Dynamic Programming Approach:** - Define a recursive function that counts unholy matrices: - It will take the current row index and the previous row as parameters. - For each call, generate all possible configurations of the next two rows (2^16 possibilities) and check if each configuration keeps the matrix unholy. - Keep a memoization table to store already computed configurations to avoid recomputation. 4. **Main Function:** - Initialize the count of unholy matrices. - Start the recursive counting process from the first row. ### C Implementation Here is the C code that follows the plan:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | #include <stdio.h> #define ROWS 8 #define COLS 8 // Function to check if a matrix is unholy int is_unholy(unsigned long current_row, unsigned long prev_row, unsigned long next_row) { for (int col = 0; col < COLS; col++) { if (current_row & (1UL << col)) { // If current cell is 1 // Check if isolated int isolated = 1; if (prev_row & (1UL << col)) isolated = 0; // Check above if (next_row & (1UL << col)) isolated = 0; // Check below if (col > 0 && (current_row & (1UL << (col - 1)))) isolated = 0; // Check left if (col < COLS - 1 && (current_row & (1UL << (col + 1)))) isolated = 0; // Check right if (isolated) { return 0; // Found an isolated 1 } } } return 1; // No isolated 1s found } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_row) { if (row == ROWS) return 1; // Base case: if we reached the end of rows unsigned long total_count = 0; // Enumerate all possible combinations for the next two rows for (unsigned long next_row = 0; next_row < (1UL << COLS); next_row++) { if (is_unholy(next_row, prev_row, (row < ROWS - 1) ? 0 : 0)) { // Check if next_row is unholy with prev_row total_count += count_unholy_matrices(row + 1, next_row); } } return total_count; } int main() { unsigned long total_unholy = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy); return 0; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | #include <stdio.h> #define ROWS 8 #define COLS 8 // Function to check if a matrix is unholy int is_unholy(unsigned long current_row, unsigned long prev_row, unsigned long next_row) { for (int col = 0; col < COLS; col++) { if (current_row & (1UL << col)) { // If current cell is 1 // Check if isolated int isolated = 1; if (prev_row & (1UL << col)) isolated = 0; // Check above if (next_row & (1UL << col)) isolated = 0; // Check below if (col > 0 && (current_row & (1UL << (col - 1)))) isolated = 0; // Check left if (col < COLS - 1 && (current_row & (1UL << (col + 1)))) isolated = 0; // Check right if (isolated) { return 0; // Found an isolated 1 } } } return 1; // No isolated 1s found } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_row) { if (row == ROWS) return 1; // Base case: if we reached the end of rows unsigned long total_count = 0; // Enumerate all possible combinations for the next two rows for (unsigned long next_row = 0; next_row < (1UL << COLS); next_row++) { if (is_unholy(next_row, prev_row, (row < ROWS - 1) ? 0 : 0)) { // Check if next_row is unholy with prev_row total_count += count_unholy_matrices(row + 1, next_row); } } return total_count; } int main() { unsigned long total_unholy = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy); return 0; } |
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | #include <stdio.h> #define ROWS 8 #define COLS 8 // Function to check if a matrix is unholy int is_unholy(unsigned long current_row, unsigned long prev_row, unsigned long next_row) { for (int col = 0; col < COLS; col++) { if (current_row & (1UL << col)) { // If current cell is 1 // Check if isolated int isolated = 1; if (prev_row & (1UL << col)) isolated = 0; // Check above if (next_row & (1UL << col)) isolated = 0; // Check below if (col > 0 && (current_row & (1UL << (col - 1)))) isolated = 0; // Check left if (col < COLS - 1 && (current_row & (1UL << (col + 1)))) isolated = 0; // Check right if (isolated) { return 0; // Found an isolated 1 } } } return 1; // No isolated 1s found } // Recursive function to count unholy matrices unsigned long count_unholy_matrices(int row, unsigned long prev_row) { if (row == ROWS) return 1; // Base case: if we reached the end of rows unsigned long total_count = 0; // Enumerate all possible combinations for the next two rows for (unsigned long next_row = 0; next_row < (1UL << COLS); next_row++) { if (is_unholy(next_row, prev_row, (row < ROWS - 1) ? 0 : 0)) { // Check if next_row is unholy with prev_row total_count += count_unholy_matrices(row + 1, next_row); } } return total_count; } int main() { unsigned long total_unholy = count_unholy_matrices(0, 0); printf("Total number of unholy 8x8 matrices: %lu\n", total_unholy); return 0; } |
Timeout: function took too long to complete
Testing if the previous output contains the string 1121231537486377866
: False
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
A binary 8x8 matrix is 'unholy' if there are no isolated 1s. A 1 is isolated if there isn't another 1 in any of the 4 direct cardinal directions. Write a C program that counts the total number of unholy 8x8 matricies.To solve this question: - Use bit arithmetic and an unsigned long to represent the matrix. - Write a function is_unholy that tests if a matrix is unholy by bit-shifting and masking. Use a dynamic program to count the number of unholy matricies. - Recurse on the number of rows the matrix has. - Enumerate all 2^16 next two rows. This is enough to completely isolate the prior solutions from the next. Write out a plan for the program, and then implement the plan in C.
Certainly! Below is a comprehensive plan for the C program that counts the total number of 'unholy' 8x8 binary matrices using bit arithmetic. ### Plan 1. **Data Representation**: - Represent an 8x8 binary matrix using an `unsigned long` (64 bits). Each bit represents a cell in the matrix (1 for filled, 0 for empty). 2. **Define Functions**: - `is_unholy(unsigned long matrix)`: This function checks if a given 8x8 matrix is 'unholy' (i.e., contains no isolated 1s). - Use bitwise operations to check for the presence of isolated 1s. - `count_unholy_matrices(int row, unsigned long previous_row, unsigned long current_row)`: This function uses recursion to count the number of unholy matrices. - Base Case: If `row` is 8, it means we have filled all rows, so we return 1 if the current matrix is unholy. - Recursive Case: Iterate through all possible configurations of the next two rows (using a loop from 0 to 65535 since 2^16 = 65536). - Call `is_unholy` to check if the complete matrix (composed of previous and current rows) remains unholy. 3. **Main Function**: - Initialize a counter to keep track of the total number of unholy matrices. - Start recursion from the first row with zeroed previous and current rows. 4. **Output the Results**: Print the total count of unholy matrices. ### C Implementation Here’s how the implementation looks in C:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | #include <stdio.h> // Function to check if a matrix is 'unholy' int is_unholy(unsigned long matrix) { for (int i = 0; i < 64; i++) { // Check if the current bit is 1 if (matrix & (1UL << i)) { // Check all four cardinal directions int up = (i >= 8) ? (matrix & (1UL << (i - 8))) : 0; // Up int down = (i < 56) ? (matrix & (1UL << (i + 8))) : 0; // Down int left = (i % 8 > 0) ? (matrix & (1UL << (i - 1))) : 0; // Left int right = (i % 8 < 7) ? (matrix & (1UL << (i + 1))) : 0; // Right // If no neighbors are 1, this 1 is isolated if (!up && !down && !left && !right) { return 0; // Isolated 1 found } } } return 1; // No isolated 1s found } // Recursive function to count unholy matrices long long count_unholy_matrices(int row, unsigned long previous_row, unsigned long current_row) { if (row == 8) { // Check if the current full matrix is unholy return is_unholy(previous_row | current_row); } long long count = 0; // Iterate through all possible configurations for two rows (16 bits) for (unsigned long next_row = 0; next_row < (1UL << 16); next_row++) { count += count_unholy_matrices(row + 2, current_row, next_row); } return count; } int main() { long long total_count = 0; total_count = count_unholy_matrices(0, 0, 0); printf("Total number of unholy 8x8 matrices: %lld\n", total_count); return 0; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | #include <stdio.h> // Function to check if a matrix is 'unholy' int is_unholy(unsigned long matrix) { for (int i = 0; i < 64; i++) { // Check if the current bit is 1 if (matrix & (1UL << i)) { // Check all four cardinal directions int up = (i >= 8) ? (matrix & (1UL << (i - 8))) : 0; // Up int down = (i < 56) ? (matrix & (1UL << (i + 8))) : 0; // Down int left = (i % 8 > 0) ? (matrix & (1UL << (i - 1))) : 0; // Left int right = (i % 8 < 7) ? (matrix & (1UL << (i + 1))) : 0; // Right // If no neighbors are 1, this 1 is isolated if (!up && !down && !left && !right) { return 0; // Isolated 1 found } } } return 1; // No isolated 1s found } // Recursive function to count unholy matrices long long count_unholy_matrices(int row, unsigned long previous_row, unsigned long current_row) { if (row == 8) { // Check if the current full matrix is unholy return is_unholy(previous_row | current_row); } long long count = 0; // Iterate through all possible configurations for two rows (16 bits) for (unsigned long next_row = 0; next_row < (1UL << 16); next_row++) { count += count_unholy_matrices(row + 2, current_row, next_row); } return count; } int main() { long long total_count = 0; total_count = count_unholy_matrices(0, 0, 0); printf("Total number of unholy 8x8 matrices: %lld\n", total_count); return 0; } |
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | #include <stdio.h> // Function to check if a matrix is 'unholy' int is_unholy(unsigned long matrix) { for (int i = 0; i < 64; i++) { // Check if the current bit is 1 if (matrix & (1UL << i)) { // Check all four cardinal directions int up = (i >= 8) ? (matrix & (1UL << (i - 8))) : 0; // Up int down = (i < 56) ? (matrix & (1UL << (i + 8))) : 0; // Down int left = (i % 8 > 0) ? (matrix & (1UL << (i - 1))) : 0; // Left int right = (i % 8 < 7) ? (matrix & (1UL << (i + 1))) : 0; // Right // If no neighbors are 1, this 1 is isolated if (!up && !down && !left && !right) { return 0; // Isolated 1 found } } } return 1; // No isolated 1s found } // Recursive function to count unholy matrices long long count_unholy_matrices(int row, unsigned long previous_row, unsigned long current_row) { if (row == 8) { // Check if the current full matrix is unholy return is_unholy(previous_row | current_row); } long long count = 0; // Iterate through all possible configurations for two rows (16 bits) for (unsigned long next_row = 0; next_row < (1UL << 16); next_row++) { count += count_unholy_matrices(row + 2, current_row, next_row); } return count; } int main() { long long total_count = 0; total_count = count_unholy_matrices(0, 0, 0); printf("Total number of unholy 8x8 matrices: %lld\n", total_count); return 0; } |
Timeout: function took too long to complete
Testing if the previous output contains the string 1121231537486377866
: False