8线程的8皇后程序

#include <stdio.h>
#include <pthread.h>int ON[] = { 0x8000, 0x4000, 0x2000, 0x1000, 0x0800, 0x0400, 0x0200, 0x0100 };
int _b[8][8], cnt[8];
pthread_t tid[8];void search (int i, int cy) {
// (idx, current_y)int*  b = _b[i];for (int x = 0; x < 8; x++) {const int o = b[cy] = ON[x];const int p = o << cy, q = o >> cy;bool ok = true;for (int y = 0; y < cy; y++) {if (b[y] == o || (b[y] << y) & p || (b[y] >> y) & q) {ok = false;break;}}if (!ok) continue;if (cy == 7) ++cnt[i];else search(i, cy + 1);}
}void* tfn (void* arg) {int i = int(long(arg));_b[i][0] = ON[i]; search(i, 1); return 0;
}int main () {for (int i = 0; i < 8; i++) pthread_create(tid+i, NULL, tfn, (void*)long(i));for (int i = 0; i < 8; i++) pthread_join(tid[i], NULL);int n = 0;for (int i = 0; i < 8; i++) printf("%d\n", n += cnt[i]);
}