#include #define ll long long using namespace std; int main() { int a[9] = {1, 2, 3, 4, 5, 6, 7, 8, 9}; int res = 0; do { int x1 = a[0] + a[1] + a[2] + a[3]; int x2 = a[3] + a[4] + a[5] + a[6]; int x3 = a[6] + a[7] + a[8] + a[0]; if (x1 == x2 && x2 == x3) { res++; } } while (next_permutation(a, a + 9)); //全排列 cout << res / 3 / 2 << endl; //翻转除以3,镜像除以2 return 0; }