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int printf();
void *calloc();
int Q;
int N;
int **t;
print() {
int x;
int y;
for (y=0; y<Q; y++) {
for (x=0; x<Q; x++)
if (t[x][y])
printf(" Q");
else
printf(" .");
printf("\n");
}
printf("\n");
}
chk(int x, int y) {
int i;
int r;
for (r=i=0; i<Q; i++) {
r = r + t[x][i];
r = r + t[i][y];
if (x+i < Q & y+i < Q)
r = r + t[x+i][y+i];
if (x+i < Q & y-i >= 0)
r = r + t[x+i][y-i];
if (x-i >= 0 & y+i < Q)
r = r + t[x-i][y+i];
if (x-i >= 0 & y-i >= 0)
r = r + t[x-i][y-i];
}
return r;
}
go(int y) {
int x;
if (y == Q) {
print();
N++;
return 0;
}
for (x=0; x<Q; x++)
if (chk(x, y) == 0) {
t[x][y]++;
go(y+1);
t[x][y]--;
}
}
main(int ac, void **av) {
int i;
Q = 8;
if (ac >= 2)
Q = atoi(av[1]);
t = calloc(Q, sizeof(int *));
for (i=0; i<Q; i++)
t[i] = calloc(Q, sizeof(int));
go(0);
printf("found %d solutions\n", N);
}
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