Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
### Explanation of the Function The given function `count` simulates a grid of size 8x8 where each cell can either be alive (1) or dead (0). It iterates through all possible configurations of this grid (16 values, as each half byte can be either 0 or 1), counts how many configurations remain unchanged after applying rules to the cells based on their neighbors. Specifically, a cell will die if it is alive and all of its orthogonal neighbors (up, down, left, right) are dead. The function ultimately returns the count of configurations that remain unchanged. ### Ways to Shorten the Function 1. **Variable Naming and Scope**: Use shorter variable names and limit the scope of variables. 2. **Bit Manipulation**: Simplify bit manipulation using fewer operations and avoid repeated expressions. 3. **Loop Optimization**: Consolidate loops and use logical operations effectively. 4. **Inline Calculations**: Combine calculations into single lines where possible. ### Shortened Function Here's a significantly shortened version of the original function using the above approaches:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | int count() { int c = 0; for (int i = 0; i < 1 << 16; i++) { unsigned long long a = ((i & 0xf) << 9) | ((i & 0xf0) << 5) | ((i & 0xf00) << 1) | ((i & 0xf000) >> 3); unsigned long long t = a; for (int r = 1; r < 7; r++) for (int j = 1; j < 7; j++) { int p = r * 8 + j, s = ((t >> (p-8)) & 1) + ((t >> (p-1)) & 1) + ((t >> (p+8)) & 1) + ((t >> (p+1)) & 1); if ((t >> p & 1) && s == 0) a &= ~(1ULL << p); } c += (a == t); } return c; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | int count() { int c = 0; for (int i = 0; i < 1 << 16; i++) { unsigned long long a = ((i & 0xf) << 9) | ((i & 0xf0) << 5) | ((i & 0xf00) << 1) | ((i & 0xf000) >> 3); unsigned long long t = a; for (int r = 1; r < 7; r++) for (int j = 1; j < 7; j++) { int p = r * 8 + j, s = ((t >> (p-8)) & 1) + ((t >> (p-1)) & 1) + ((t >> (p+8)) & 1) + ((t >> (p+1)) & 1); if ((t >> p & 1) && s == 0) a &= ~(1ULL << p); } c += (a == t); } return c; } |
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 | int count() { int c = 0; for (int i = 0; i < 1 << 16; i++) { unsigned long long a = ((i & 0xf) << 9) | ((i & 0xf0) << 5) | ((i & 0xf00) << 1) | ((i & 0xf000) >> 3); unsigned long long t = a; for (int r = 1; r < 7; r++) for (int j = 1; j < 7; j++) { int p = r * 8 + j, s = ((t >> (p-8)) & 1) + ((t >> (p-1)) & 1) + ((t >> (p+8)) & 1) + ((t >> (p+1)) & 1); if ((t >> p & 1) && s == 0) a &= ~(1ULL << p); } c += (a == t); } return c; } #include<stdio.h> #include<stdlib.h> int main() { int answer = count(); int expected = 27488; if (answer != expected) { printf("Wrong answer; got %d instead of %d.\n", answer, expected); exit(1); } printf("All tests passed\n"); } |
Wrong answer; got 58051 instead of 27488.
Testing if the previous output contains the string All tests passed
: False
Resulting in output: False
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
### Explanation of the Function The given function `count` simulates a cellular automaton on an 8x8 grid based on binary representations of states. Each cell can either be alive (1) or dead (0). The function iterates through all possible configurations of the grid, applying a rule where a live cell dies if all its neighbors (up, down, left, right) are dead. The function counts how many configurations remain unchanged after applying this rule and returns that count. ### Ways to Shorten the Function 1. **Remove Redundant Variables**: The variable `temp` is unnecessary since we can use `array` directly. 2. **Combine Operations**: We can combine some of the bitwise operations and eliminate repetitive calculations. 3. **Use Helper Macros or Inline Functions**: To reduce the length of neighbor calculations, we can use macros or inline functions to deal with bit shifts more concisely. 4. **Reduce Loop and Condition Length**: By using more compact expressions, we can reduce the number of lines and characters. ### Shortened Function Here’s a significantly shortened version of the function:
1 2 3 4 5 6 7 8 9 10 11 12 13 | int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long long a=((i&0xf)<<9)|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a; for(int r=1;r<7;r++) for(int j=1;j<7;j++){ int s=(b>>((r*8)+j))&1,t=((b>>((r-1)*8+j))&1)+((b>>((r+1)*8+j))&1)+((b>>(r*8+j-1))&1)+((b>>(r*8+j+1))&1); if(t==0&&s) a&=~(1ULL<<((r*8)+j)); } c+=a==b; } return c; } |
1 2 3 4 5 6 7 8 9 10 11 12 13 | int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long long a=((i&0xf)<<9)|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a; for(int r=1;r<7;r++) for(int j=1;j<7;j++){ int s=(b>>((r*8)+j))&1,t=((b>>((r-1)*8+j))&1)+((b>>((r+1)*8+j))&1)+((b>>(r*8+j-1))&1)+((b>>(r*8+j+1))&1); if(t==0&&s) a&=~(1ULL<<((r*8)+j)); } c+=a==b; } return c; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | #include <stdio.h> int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long long a=((i&0xf)<<9)|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a; for(int r=1;r<7;r++) for(int j=1;j<7;j++){ int s=(b>>((r*8)+j))&1,t=((b>>((r-1)*8+j))&1)+((b>>((r+1)*8+j))&1)+((b>>(r*8+j-1))&1)+((b>>(r*8+j+1))&1); if(t==0&&s) a&=~(1ULL<<((r*8)+j)); } c+=a==b; } return c; } |
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 | #include <stdio.h> int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long long a=((i&0xf)<<9)|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a; for(int r=1;r<7;r++) for(int j=1;j<7;j++){ int s=(b>>((r*8)+j))&1,t=((b>>((r-1)*8+j))&1)+((b>>((r+1)*8+j))&1)+((b>>(r*8+j-1))&1)+((b>>(r*8+j+1))&1); if(t==0&&s) a&=~(1ULL<<((r*8)+j)); } c+=a==b; } return c; } #include<stdio.h> #include<stdlib.h> int main() { int answer = count(); int expected = 27488; if (answer != expected) { printf("Wrong answer; got %d instead of %d.\n", answer, expected); exit(1); } printf("All tests passed\n"); } |
Wrong answer; got 58051 instead of 27488.
Testing if the previous output contains the string All tests passed
: False
Resulting in output: False
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
### Explanation The function `count` simulates a grid of cells (8x8) where each cell can be either alive (1) or dead (0). It iterates over all possible configurations of the grid (16-bit integer, since each cell can be represented by a bit). For each configuration, it checks the state of each cell based on its neighbors (top, left, bottom, right). If a cell is alive but all its neighbors are dead, it is marked dead. Finally, it counts how many configurations remain unchanged after this process. ### Ways to Shorten the Function 1. **Variable Names**: Use shorter variable names for clarity. 2. **Inline Calculations**: Combine operations wherever possible to reduce the number of lines. 3. **Reduce Loop Logic**: Streamline the nested loops and conditionals. 4. **Bit Manipulation**: Utilize bitwise operations more effectively to minimize repeated logic. ### Shortened Function
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long a=((i&0xf)<<9)|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3); unsigned long t=a; for(int r=1;r<7;r++) for(int j=1;j<7;j++){ int p=r*8+j,t1=(r-1)*8+j,t2=r*8+(j-1),t3=(r+1)*8+j,t4=r*8+(j+1); int s=(t>>t1&1)+(t>>t2&1)+(t>>t3&1)+(t>>t4&1); if(s==0 && (t>>p&1)) a&=~(1UL<<p); } c+=a==t; } return c; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long a=((i&0xf)<<9)|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3); unsigned long t=a; for(int r=1;r<7;r++) for(int j=1;j<7;j++){ int p=r*8+j,t1=(r-1)*8+j,t2=r*8+(j-1),t3=(r+1)*8+j,t4=r*8+(j+1); int s=(t>>t1&1)+(t>>t2&1)+(t>>t3&1)+(t>>t4&1); if(s==0 && (t>>p&1)) a&=~(1UL<<p); } c+=a==t; } return c; } |
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 | int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long a=((i&0xf)<<9)|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3); unsigned long t=a; for(int r=1;r<7;r++) for(int j=1;j<7;j++){ int p=r*8+j,t1=(r-1)*8+j,t2=r*8+(j-1),t3=(r+1)*8+j,t4=r*8+(j+1); int s=(t>>t1&1)+(t>>t2&1)+(t>>t3&1)+(t>>t4&1); if(s==0 && (t>>p&1)) a&=~(1UL<<p); } c+=a==t; } return c; } #include<stdio.h> #include<stdlib.h> int main() { int answer = count(); int expected = 27488; if (answer != expected) { printf("Wrong answer; got %d instead of %d.\n", answer, expected); exit(1); } printf("All tests passed\n"); } |
Wrong answer; got 58051 instead of 27488.
Testing if the previous output contains the string All tests passed
: False
Resulting in output: False
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
### Explanation of the Function The function `count` counts how many configurations of an 8x8 grid (represented as a bit pattern in a 16-bit integer) remain unchanged after applying the rules of a cellular automaton similar to Conway's Game of Life. Each cell in the grid can either be alive (1) or dead (0). A cell will die if all its neighboring cells are dead, and the function checks this condition for each possible configuration of the grid. ### Ways to Shorten the Function 1. **Eliminate Redundant Variables**: The variable `temp` can be removed since we can use `array` directly for calculations. 2. **Inline Expressions**: Several computations can be done inline rather than assigning them to variables (like `pos`, `topPos`, etc.). 3. **Loop Unification**: We can replace nested loops with a single loop where possible. 4. **Bitwise Operations**: We can use fewer lines for bitwise operations by combining them. ### Shortened Function Here’s a much shorter version of the function:
1 2 3 4 5 6 7 8 9 10 11 12 13 | int count() { int c=0; for(int i=0;i<1<<16;i++){ unsigned long long a=(i&0xf)<<9|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a; for(int j=1;j<7;j++) for(int k=1;k<7;k++){ int s=(((b>>k+8*j)&1)+((b>>k-1+8*j)&1)+((b>>k+8*(j-1))&1)+((b>>k+8*(j+1))&1)); a&=~(1ULL<<(k+8*j)*(s==0&&((b>>k+8*j)&1))); } c+=a==b; } return c; } |
1 2 | int count() { int c=0;for(int i=0;i<1<<16;i++){unsigned long long a=(i&0xf)<<9|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a;for(int j=1;j<7;j++)for(int k=1;k<7;k++){int s=(((b>>k+8*j)&1)+((b>>k-1+8*j)&1)+((b>>k+8*(j-1))&1)+((b>>k+8*(j+1))&1));a&=~(1ULL<<(k+8*j)*(s==0&&((b>>k+8*j)&1)));}c+=a==b;}return c;} |
I extracted the following code from that output:
1 2 3 4 | #include <stdio.h> int count() { int c=0;for(int i=0;i<1<<16;i++){unsigned long long a=(i&0xf)<<9|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a;for(int j=1;j<7;j++)for(int k=1;k<7;k++){int s=(((b>>k+8*j)&1)+((b>>k-1+8*j)&1)+((b>>k+8*(j-1))&1)+((b>>k+8*(j+1))&1));a&=~(1ULL<<(k+8*j)*(s==0&&((b>>k+8*j)&1)));}c+=a==b;}return c;} |
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 | #include <stdio.h> int count() { int c=0;for(int i=0;i<1<<16;i++){unsigned long long a=(i&0xf)<<9|((i&0xf0)<<5)|((i&0xf00)<<1)|((i&0xf000)>>3),b=a;for(int j=1;j<7;j++)for(int k=1;k<7;k++){int s=(((b>>k+8*j)&1)+((b>>k-1+8*j)&1)+((b>>k+8*(j-1))&1)+((b>>k+8*(j+1))&1));a&=~(1ULL<<(k+8*j)*(s==0&&((b>>k+8*j)&1)));}c+=a==b;}return c;} #include<stdio.h> #include<stdlib.h> int main() { int answer = count(); int expected = 27488; if (answer != expected) { printf("Wrong answer; got %d instead of %d.\n", answer, expected); exit(1); } printf("All tests passed\n"); } |
Wrong answer; got 65536 instead of 27488.
Testing if the previous output contains the string All tests passed
: False
Resulting in output: False
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
Code golf this function to be a lot shorter. You only get points if it's <300 bytes (not counting whitespace). Keep the function named `count`.
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 | int count() { int ROWS = 8; int COLS = 8; int count = 0; for (int i = 0; i < 1<<16; i++) { long long unsigned int array = ((i & 0xf) << 9) | ((i & 0xf0) << (9 + 8 - 4)) | ((i & 0xf00) << (9 + 8 - 4 + 8 - 4)) | ((i & 0xf000) << (9 + 8 - 4 + 8 - 4 + 8 - 4)); long long unsigned int init = array; long long unsigned int temp = array; for (int i = 1; i < ROWS - 1; i++) { for (int j = 1; j < COLS - 1; j++) { // Calculate bit positions int pos = i * COLS + j; int topPos = (i - 1) * COLS + j; int leftPos = i * COLS + (j - 1); int bottomPos = (i + 1) * COLS + j; int rightPos = i * COLS + (j + 1); // Get the values of the neighbors int cell = (temp >> pos) & 1; int top = (temp >> topPos) & 1; int left = (temp >> leftPos) & 1; int bottom = (temp >> bottomPos) & 1; int right = (temp >> rightPos) & 1; // Sum the values of the neighbors int sum = top + left + bottom + right; // Update the cell if all neighbors are 0 and the cell itself is 1 if (sum == 0 && cell == 1) { array &= ~(1ULL << pos); } } } count += (init == array); } return count; } |
### Explanation of the Function The function `count` simulates a 2D cellular automaton on an 8x8 grid. It iterates through all possible states of the grid (represented as a 16-bit integer) and applies a rule that checks the state of each cell and its four direct neighbors (up, down, left, right). If a cell is alive (1) and all its neighbors are dead (0), it is set to dead (0). The function counts how many configurations remain unchanged after applying this rule and returns that count. ### Ways to Shorten the Function 1. **Variable Names**: Use shorter variable names, such as `c` instead of `count`, `r` instead of `ROWS`, etc. 2. **Combine Logic**: Combine similar operations where possible, e.g., using bitwise operations directly in conditions. 3. **Loop Optimization**: Use fewer nested loops or a single loop to handle neighbor checks in a more compact way. 4. **Remove Redundant Variables**: Eliminate any unnecessary variables that are not required for the logic. ### Shortened Version of the Function Here's a shortened version of the `count` function, aiming for brevity:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | int count() { int c = 0; for (int i = 0; i < 1<<16; i++) { unsigned long long a = i & 0xFFFF; unsigned long long b = a; for (int j = 1; j < 7; j++) { for (int k = 1; k < 7; k++) { int s = ((b >> (j * 8 + k - 1)) & 1) + ((b >> (j * 8 + k + 1)) & 1) + ((b >> ((j - 1) * 8 + k)) & 1) + ((b >> ((j + 1) * 8 + k)) & 1); if (s == 0 && ((b >> (j * 8 + k)) & 1)) a &= ~(1ULL << (j * 8 + k)); } } c += (a == b); } return c; } |
1 2 3 4 5 6 7 8 9 10 11 12 | int count() { int c = 0; for (int i = 0; i < 1<<16; i++) { unsigned long long a = i, b = a; for (int j = 1; j < 7; j++) for (int k = 1; k < 7; k++) if (((b >> (j * 8 + k)) & 1) && !(((b >> (j * 8 + k - 1)) & 1) + ((b >> (j * 8 + k + 1)) & 1) + ((b >> ((j - 1) * 8 + k)) & 1) + ((b >> ((j + 1) * 8 + k)) & 1))) a &= ~(1ULL << (j * 8 + k)); c += (a == b); } return c; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | #include <stdio.h> int count() { int c = 0; for (int i = 0; i < 1<<16; i++) { unsigned long long a = i, b = a; for (int j = 1; j < 7; j++) for (int k = 1; k < 7; k++) if (((b >> (j * 8 + k)) & 1) && !(((b >> (j * 8 + k - 1)) & 1) + ((b >> (j * 8 + k + 1)) & 1) + ((b >> ((j - 1) * 8 + k)) & 1) + ((b >> ((j + 1) * 8 + k)) & 1))) a &= ~(1ULL << (j * 8 + k)); c += (a == b); } return c; } |
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 | #include <stdio.h> int count() { int c = 0; for (int i = 0; i < 1<<16; i++) { unsigned long long a = i, b = a; for (int j = 1; j < 7; j++) for (int k = 1; k < 7; k++) if (((b >> (j * 8 + k)) & 1) && !(((b >> (j * 8 + k - 1)) & 1) + ((b >> (j * 8 + k + 1)) & 1) + ((b >> ((j - 1) * 8 + k)) & 1) + ((b >> ((j + 1) * 8 + k)) & 1))) a &= ~(1ULL << (j * 8 + k)); c += (a == b); } return c; } #include<stdio.h> #include<stdlib.h> int main() { int answer = count(); int expected = 27488; if (answer != expected) { printf("Wrong answer; got %d instead of %d.\n", answer, expected); exit(1); } printf("All tests passed\n"); } |
Wrong answer; got 44352 instead of 27488.
Testing if the previous output contains the string All tests passed
: False
Resulting in output: True