题解 | #Sum of Factorials#

#include <cstdio>
using namespace std;
int a[11];
int main() {
    a[0] = 1; //a[0]也要算进去！
    a[1] = 1;
    for (int i = 2; i < 11; i++)
        a[i] = a[i - 1] * i;
    int n;
    while (scanf("%d", &n) != EOF) {
        int t = n;
        for (int i = 10; i >= 0; i--) {//n！每两个数相隔大 故可此方法
            if (t >= a[i]) {
                t -= a[i];
            }
        }
        if (t > 0) {
            printf("NO\n");
        } else {
            printf("YES\n");
        }

    }
}