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#include <stdio.h>
#include <stdlib.h>
#define ROWS 100
#define COLS 100
void new(int*** a) {
int i;
*a = (int**) malloc(ROWS * sizeof(int*));
for(i=0; i<ROWS; i++)
(*a)[i] = (int*) malloc(COLS * sizeof(int));
}
void delete(int** a) {
int i;
for(i=0; i<ROWS; i++)
free(a[i]);
free(a);
}
void copy(int** src, int** dst) {
int i, j;
for(i=0; i<ROWS; i++)
for(j=0; j<COLS; j++)
dst[i][j] = src[i][j];
}
void readinto(int** a) {
int i, j, ch;
for(i=0; i<ROWS; i++) {
for(j=0; j<COLS; j++) {
ch = getchar();
switch(ch) {
case '.': a[i][j] = 0; break;
case '#': a[i][j] = 1;
}
}
getchar(); // '\n'
}
}
int ncount(int** a, int r, int c) {
int n = 0, i, j;
for(i=-1; i<2; i++)
for(j=-1; j<2; j++)
if((r+i)>=0 && (r+i)<ROWS && (c+j)>=0 && (c+j)<COLS && !(i == 0 && j == 0))
n += a[r+i][c+j];
return n;
}
void step(int** old, int** new) {
int i, j, c;
for(i=0; i<ROWS; i++)
for(j=0; j<COLS; j++) {
c = ncount(old, i, j);
if(old[i][j]) {
if(c == 2 || c == 3) new[i][j] = 1;
else new[i][j] = 0;
} else {
if(c == 3) new[i][j] = 1;
else new[i][j] = 0;
}
}
}
void corners(int** a) {
a[0][0] = a[ROWS-1][0] = a[0][COLS-1] = a[ROWS-1][COLS-1] = 1;
}
int numlights(int** a) {
int n = 0, i, j;
for(i=0; i<ROWS; i++)
for(j=0; j<COLS; j++)
n += a[i][j];
return n;
}
int main() {
int i, **input, **this, **that;
new(&input);
new(&this);
new(&that);
readinto(input);
copy(input, this);
for(i=0; i<50; i++) {
step(this, that);
step(that, this);
}
printf("Number of lights: %d\n", numlights(this));
copy(input, this);
corners(this);
for(i=0; i<50; i++) {
step(this, that);
corners(that);
step(that, this);
corners(this);
}
printf("Number of lights: %d\n", numlights(this));
delete(input);
delete(this);
delete(that);
return 0;
}
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