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; } |
1. The function `count` generates all possible 8x8 binary patterns and counts how many of them are "still lifes" in the Game of Life. A still life is a pattern that doesn't change after applying the rules of the Game of Life once. 2. To make the function shorter, we can: - Use bitwise operations to manipulate the binary patterns more efficiently. - Use lookup tables or precomputed values to avoid redundant calculations. - Combine nested loops or use more concise loop structures. 3. Here's a shorter version of the `count` function:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | int count() { static const long long t[]={0x0000000000000000,0x0000000000000003, 0x000000000000000c,0x0000000000000030,0x00000000000000c0,0x0000000000000300, 0x0000000000000c00,0x0000000000003000,0x000000000000c000,0x0000000000030000, 0x00000000000c0000,0x0000000000300000,0x0000000000c00000,0x0000000003000000, 0x000000000c000000,0x0000000030000000,0x00000000c0000000,0x0000000300000000, 0x0000000c00000000,0x0000003000000000,0x000000c000000000,0x0000030000000000, 0x00000c0000000000,0x0000300000000000,0x0000c00000000000,0x0003000000000000, 0x000c000000000000,0x0030000000000000,0x00c0000000000000,0x0300000000000000, 0x0c00000000000000,0x3000000000000000}; int r=0; for(long long i=0x0000000000003c3c;i<0x0000fffffffcfcfc;i+=0x0001010101010101) if(!(t[(i>>48)&0x1f]|(t[(i>>42)&0x3f]<<6)|(t[(i>>36)&0x3f]<<12)| (t[(i>>30)&0x3f]<<18)|(t[(i>>24)&0x3f]<<24)|(t[(i>>18)&0x3f]<<30)| (t[(i>>12)&0x3f]<<36)|(t[(i>>6)&0x3f]<<42)|t[i&0x3f]<<48))r++; return r; } |
1 2 3 4 5 6 7 8 9 10 11 12 | int count(){static const long long t[]={0x0000000000000000,0x0000000000000003, 0x000000000000000c,0x0000000000000030,0x00000000000000c0,0x0000000000000300, 0x0000000000000c00,0x0000000000003000,0x000000000000c000,0x0000000000030000, 0x00000000000c0000,0x0000000000300000,0x0000000000c00000,0x0000000003000000, 0x000000000c000000,0x0000000030000000,0x00000000c0000000,0x0000000300000000, 0x0000000c00000000,0x0000003000000000,0x000000c000000000,0x0000030000000000, 0x00000c0000000000,0x0000300000000000,0x0000c00000000000,0x0003000000000000, 0x000c000000000000,0x0030000000000000,0x00c0000000000000,0x0300000000000000, 0x0c00000000000000,0x3000000000000000};int r=0;for(long long i=0x0000000000003c3c; i<0x0000fffffffcfcfc;i+=0x0001010101010101)r+=!(t[(i>>48)&0x1f]|(t[(i>>42)&0x3f]<<6)| (t[(i>>36)&0x3f]<<12)|(t[(i>>30)&0x3f]<<18)|(t[(i>>24)&0x3f]<<24)|(t[(i>>18)&0x3f]<<30)| (t[(i>>12)&0x3f]<<36)|(t[(i>>6)&0x3f]<<42)|t[i&0x3f]<<48);return r;} |
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 | #include <stdint.h> int count() { static const long long t[] = {0x0000000000000000, 0x0000000000000003, 0x000000000000000c, 0x0000000000000030, 0x00000000000000c0, 0x0000000000000300, 0x0000000000000c00, 0x0000000000003000, 0x000000000000c000, 0x0000000000030000, 0x00000000000c0000, 0x0000000000300000, 0x0000000000c00000, 0x0000000003000000, 0x000000000c000000, 0x0000000030000000, 0x00000000c0000000, 0x0000000300000000, 0x0000000c00000000, 0x0000003000000000, 0x000000c000000000, 0x0000030000000000, 0x00000c0000000000, 0x0000300000000000, 0x0000c00000000000, 0x0003000000000000, 0x000c000000000000, 0x0030000000000000, 0x00c0000000000000, 0x0300000000000000, 0x0c00000000000000, 0x3000000000000000}; int r = 0; for (long long i = 0x0000000000003c3c; i < 0x0000fffffffcfcfc; i += 0x0001010101010101) if (!(t[(i >> 48) & 0x1f] | (t[(i >> 42) & 0x3f] << 6) | (t[(i >> 36) & 0x3f] << 12) | (t[(i >> 30) & 0x3f] << 18) | (t[(i >> 24) & 0x3f] << 24) | (t[(i >> 18) & 0x3f] << 30) | (t[(i >> 12) & 0x3f] << 36) | (t[(i >> 6) & 0x3f] << 42) | t[i & 0x3f] << 48)) r++; return r; } |
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 | #include <stdint.h> int count() { static const long long t[] = {0x0000000000000000, 0x0000000000000003, 0x000000000000000c, 0x0000000000000030, 0x00000000000000c0, 0x0000000000000300, 0x0000000000000c00, 0x0000000000003000, 0x000000000000c000, 0x0000000000030000, 0x00000000000c0000, 0x0000000000300000, 0x0000000000c00000, 0x0000000003000000, 0x000000000c000000, 0x0000000030000000, 0x00000000c0000000, 0x0000000300000000, 0x0000000c00000000, 0x0000003000000000, 0x000000c000000000, 0x0000030000000000, 0x00000c0000000000, 0x0000300000000000, 0x0000c00000000000, 0x0003000000000000, 0x000c000000000000, 0x0030000000000000, 0x00c0000000000000, 0x0300000000000000, 0x0c00000000000000, 0x3000000000000000}; int r = 0; for (long long i = 0x0000000000003c3c; i < 0x0000fffffffcfcfc; i += 0x0001010101010101) if (!(t[(i >> 48) & 0x1f] | (t[(i >> 42) & 0x3f] << 6) | (t[(i >> 36) & 0x3f] << 12) | (t[(i >> 30) & 0x3f] << 18) | (t[(i >> 24) & 0x3f] << 24) | (t[(i >> 18) & 0x3f] << 30) | (t[(i >> 12) & 0x3f] << 36) | (t[(i >> 6) & 0x3f] << 42) | t[i & 0x3f] << 48)) r++; return r; } #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 0 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; } |
1. The function `count()` counts the number of initial configurations of an 8x8 grid where no cells remain alive after the rules of Conway's Game of Life are applied. The rules state that a live cell with fewer than two live neighbors dies (underpopulation), a live cell with two or three live neighbors lives on to the next generation, and a live cell with more than three live neighbors dies (overpopulation). Additionally, a dead cell with exactly three live neighbors becomes a live cell (reproduction). 2. Here are a few ways to make the function shorter: - Use bitwise operations to represent the grid and update it efficiently. - Avoid unnecessary variable declarations and assignments. - Utilize loop unrolling and precomputation of bit shifts. - Inline small helper functions. 3. Here's a shorter version of the function:
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++){ long long b=((i&0xf)<<9)|((i&0xf0)<<17)|((i&0xf00)<<25)|((i&0xf000)<<33),n=b; for(int j=1;j<7;j++)for(int k=1;k<7;k++){ int q=j*8+k,p=n>>(q-9)&0x1e0,r=p+p>>4&0x1c0; n&=~(r==0x1c0&&(n>>q&1)<<q); } c+=(n==b); } return c; } |
1 | int count(){int c=0;for(int i=0;i<(1<<16);i++){long long b=((i&0xf)<<9)|((i&0xf0)<<17)|((i&0xf00)<<25)|((i&0xf000)<<33),n=b;for(int j=49;j<57;j++)for(int k=j&7?j&-8:49;k<57;k+=8){int q=j*8+k,p=n>>(q-9)&0x1e0,r=p+p>>4&0x1c0;n&=~(r==0x1c0&&(n>>q&1)<<q);}c+=(n==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 <stdint.h> int count() { int c = 0; for (int i = 0; i < (1 << 16); i++) { long long b = ((i & 0xf) << 9) | ((i & 0xf0) << 17) | ((i & 0xf00) << 25) | ((i & 0xf000) << 33), n = b; for (int j = 49; j < 57; j++) for (int k = j & 7 ? j & -8 : 49; k < 57; k += 8) { int q = j * 8 + k, p = n >> (q - 9) & 0x1e0, r = p + p >> 4 & 0x1c0; n &= ~(r == 0x1c0 && (n >> q & 1) << q); } c += (n == 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 <stdint.h> int count() { int c = 0; for (int i = 0; i < (1 << 16); i++) { long long b = ((i & 0xf) << 9) | ((i & 0xf0) << 17) | ((i & 0xf00) << 25) | ((i & 0xf000) << 33), n = b; for (int j = 49; j < 57; j++) for (int k = j & 7 ? j & -8 : 49; k < 57; k += 8) { int q = j * 8 + k, p = n >> (q - 9) & 0x1e0, r = p + p >> 4 & 0x1c0; n &= ~(r == 0x1c0 && (n >> q & 1) << q); } c += (n == 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.
main.c: In function 'count':
main.c:7:99: warning: left shift count >= width of type [-Wshift-count-overflow]
7 | long long b = ((i & 0xf) << 9) | ((i & 0xf0) << 17) | ((i & 0xf00) << 25) | ((i & 0xf000) << 33), n = b;
| ^~
Testing if the previous output contains the string All tests passed
: False
Resulting in output: True
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; } |
1. The function `count()` appears to be an implementation of Conway's Game of Life. It iterates through all possible initial states (2^16) of an 8x8 grid and counts the number of states that don't change after one iteration of the rules. 2. Here are a few ways the function could be shortened: - Use bit manipulation to calculate the next state instead of nested loops. - Precalculate the bit shifts and masks. - Use a lookup table for the rules instead of conditional statements. 3. Here's a shorter version of the function:
1 | int count(){int c=0,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z;for(i=0;i<1<<16;i++){for(j=k=i,l=m=n=o=0;j;o+=j&1,j>>=1)l+=(j&0x8000)>>15,m+=(j&0x4000)>>14,n+=(j&0x2000)>>13;for(p=0,q=l+m+n,r=m+o+n,s=l+o+n,t=l+m+o;q<4;q+=4)p|=1<<q;for(;r<4;r+=4)p|=1<<r+16;for(;s<4;s+=4)p|=1<<s+32;for(;t<4;t+=4)p|=1<<t+48;for(u=(k^(p|(p<<16)))|p,v=w=u,x=y=0;v;y+=v&1,v>>=1)x+=(v&0x8000)>>15;z=(1<<60)-1,c+=(x^=k)==0;}}return c;} |
1 | int count(){int c=0,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z;for(i=0;i<1<<16;i++){for(j=k=i,l=m=n=o=0;j;o+=j&1,j>>=1)l+=(j&0x8000)>>15,m+=(j&0x4000)>>14,n+=(j&0x2000)>>13;for(p=q=r=s=t=0;q<4;q++)p|=1<<q*(l+m+n>=q);for(;r<4;r++)q|=1<<r+16*(m+o+n>=r);for(;s<4;s++)r|=1<<s+32*(l+o+n>=s);for(;t<4;t++)s|=1<<t+48*(l+m+o>=t);for(u=(k^(p|q|r|s))|p|q|r|s,v=w=u,x=y=0;v;y+=v&1,v>>=1)x+=(v&0x8000)>>15;z=(1<<60)-1,c+=(x^=k)==0;}}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 16 17 18 19 20 21 | #include <stdint.h> int count(){ int c=0,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z; for(i=0;i<1<<16;i++){ for(j=k=i,l=m=n=o=0;j;o+=j&1,j>>=1) l+=(j&0x8000)>>15,m+=(j&0x4000)>>14,n+=(j&0x2000)>>13; for(p=q=r=s=t=0;q<4;q++) p|=1<<q*(l+m+n>=q); for(;r<4;r++) q|=1<<r+16*(m+o+n>=r); for(;s<4;s++) r|=1<<s+32*(l+o+n>=s); for(;t<4;t++) s|=1<<t+48*(l+m+o>=t); for(u=(k^(p|q|r|s))|p|q|r|s,v=w=u,x=y=0;v;y+=v&1,v>>=1) x+=(v&0x8000)>>15; z=(1<<60)-1,c+=(x^=k)==0; } 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 33 34 35 36 37 38 | #include <stdint.h> int count(){ int c=0,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z; for(i=0;i<1<<16;i++){ for(j=k=i,l=m=n=o=0;j;o+=j&1,j>>=1) l+=(j&0x8000)>>15,m+=(j&0x4000)>>14,n+=(j&0x2000)>>13; for(p=q=r=s=t=0;q<4;q++) p|=1<<q*(l+m+n>=q); for(;r<4;r++) q|=1<<r+16*(m+o+n>=r); for(;s<4;s++) r|=1<<s+32*(l+o+n>=s); for(;t<4;t++) s|=1<<t+48*(l+m+o>=t); for(u=(k^(p|q|r|s))|p|q|r|s,v=w=u,x=y=0;v;y+=v&1,v>>=1) x+=(v&0x8000)>>15; z=(1<<60)-1,c+=(x^=k)==0; } 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 2 instead of 27488.
main.c: In function 'count':
main.c:19:13: warning: left shift count >= width of type [-Wshift-count-overflow]
19 | z=(1<<60)-1,c+=(x^=k)==0;
| ^~
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; } |
1. The function `count()` generates all possible configurations of a 4x4 grid, where each cell can be either alive (1) or dead (0). It then simulates the Game of Life rules on each configuration, skipping the outermost cells. The function counts the number of configurations that remain unchanged after the simulation. 2. Here are a few ways to make the function shorter: - Use bitwise operations to manipulate the grid instead of nested loops. - Precalculate the shift values for each neighbor instead of computing them in the loop. - Combine conditions using bitwise operations. 3. Here's a shorter version of the function:
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){ int g=i,n,t=g; for(int j=15;j--;) for(int k=12;k--;n+=((g>>j&24)==16)) for(int l=4;l--;) if((n=g>>j&8>>k&7^(g>>j+1&8|g>>j-8&8|g>>j-1&8|g>>j+8&8))==3)g^=8>>j>>k; c+=(g==t); } return c; } |
1 | int count(){int c=0;for(int i=0;i<(1<<16);++i){int g=i,n,t=g;for(int j=15;j--;)for(int k=12;k--;n+=((g>>j&24)==16))for(int l=4;l--;)if((n=g>>j&8>>k&7^(g>>j+1&8|g>>j-8&8|g>>j-1&8|g>>j+8&8))==3)g^=8>>j>>k;c+=(g==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 | #include <stdio.h> int count() { int c=0; for(int i=0;i<(1<<16);++i){ int g=i,n,t=g; for(int j=15;j--;) for(int k=12;k--;n+=((g>>j&24)==16)) for(int l=4;l--;) if((n=g>>j&8>>k&7^(g>>j+1&8|g>>j-8&8|g>>j-1&8|g>>j+8&8))==3)g^=8>>j>>k; c+=(g==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 | #include <stdio.h> int count() { int c=0; for(int i=0;i<(1<<16);++i){ int g=i,n,t=g; for(int j=15;j--;) for(int k=12;k--;n+=((g>>j&24)==16)) for(int l=4;l--;) if((n=g>>j&8>>k&7^(g>>j+1&8|g>>j-8&8|g>>j-1&8|g>>j+8&8))==3)g^=8>>j>>k; c+=(g==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 65536 instead of 27488.
Testing if the previous output contains the string All tests passed
: False
Resulting in output: True
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; } |
1. Explanation: The function `count()` appears to be counting the number of initial states of a binary array (represented as an integer) that remain unchanged after applying the Game of Life rules. The Game of Life is a cellular automaton devised by John Conway in 1970. The function applies the rules to the inner cells of an 8x8 grid and checks if the initial state remains the same. 2. Possible ways to make it shorter: - Use bitwise operations to manipulate the array instead of nested loops. - Eliminate unnecessary variables and calculations. - Use bit-shifting and masking to access and update individual bits. 3. Shortened version:
1 | int count(){int c=0,i,j,k,l,m,n,o,p;for(i=0;i<(1<<16);i++){for(j=i,k=0;k<8;k++)for(l=0;l<8;l++)m=!!(j&(1<<(k*8+l))),n=(k&&l&&k<7&&l<7),o=n&&!!(j&(1<<(k*8+l-1)))+(k&&l<6&&!!(j&(1<<(k*8+l+1))))+(!k&&l&&!!(j&(1<<((k+1)*8+l))))+((k<7)&&l&&!!(j&(1<<((k-1)*8+l)))),p=j,j=n&&o<2?j&~(1<<(k*8+l)):o>3?j&~(1<<(k*8+l)):o==3?j|=1<<(k*8+l):j;c+=p==j;}return c;} |
1 2 3 4 5 6 7 8 9 10 | int count() { int c = 0, i, j, k, l, m, n, o, p; for (i = 0; i < (1 << 16); i++) { for (j = i, k = 0; k < 8; k++) for (l = 0; l < 8; l++) m = !!(j & (1 << (k * 8 + l))), n = (k && l && k < 7 && l < 7), o = n && !!(j & (1 << (k * 8 + l - 1))) + (k && l < 6 && !!(j & (1 << (k * 8 + l + 1)))) + (!k && l && !!(j & (1 << ((k + 1) * 8 + l)))) + ((k < 7) && l && !!(j & (1 << ((k - 1) * 8 + l)))), p = j, j = n && o < 2 ? j & ~(1 << (k * 8 + l)) : o > 3 ? j & ~(1 << (k * 8 + l)) : o == 3 ? j |= 1 << (k * 8 + l) : j; c += p == j; } return c; } |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 | #include <stdbool.h> int count() { int c = 0, i, j, k, l, m, n, o, p; for (i = 0; i < (1 << 16); i++) { for (j = i, k = 0; k < 8; k++) for (l = 0; l < 8; l++) m = !!(j & (1 << (k * 8 + l))), n = (k && l && k < 7 && l < 7), o = n && !!(j & (1 << (k * 8 + l - 1))) + (k && l < 6 && !!(j & (1 << (k * 8 + l + 1)))) + (!k && l && !!(j & (1 << ((k + 1) * 8 + l)))) + ((k < 7) && l && !!(j & (1 << ((k - 1) * 8 + l)))), p = j, j = n && o < 2 ? j & ~(1 << (k * 8 + l)) : o > 3 ? j & ~(1 << (k * 8 + l)) : o == 3 ? j |= 1 << (k * 8 + l) : j; c += p == j; } 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 | #include <stdbool.h> int count() { int c = 0, i, j, k, l, m, n, o, p; for (i = 0; i < (1 << 16); i++) { for (j = i, k = 0; k < 8; k++) for (l = 0; l < 8; l++) m = !!(j & (1 << (k * 8 + l))), n = (k && l && k < 7 && l < 7), o = n && !!(j & (1 << (k * 8 + l - 1))) + (k && l < 6 && !!(j & (1 << (k * 8 + l + 1)))) + (!k && l && !!(j & (1 << ((k + 1) * 8 + l)))) + ((k < 7) && l && !!(j & (1 << ((k - 1) * 8 + l)))), p = j, j = n && o < 2 ? j & ~(1 << (k * 8 + l)) : o > 3 ? j & ~(1 << (k * 8 + l)) : o == 3 ? j |= 1 << (k * 8 + l) : j; c += p == j; } 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