网页在线客服系统代码_成都彭超艺术设计有限公司_聚合搜索引擎接口_公众号推广方案

#include <iostream>
using namespace std;
int n, k;
const int N = 25;
int a[N];
int path;
int ret;bool isprime(int x)
{if (x <= 1) return false;else{for (int i = 2; i <= x / i; i++){if (x % i == 0){return false;}}}return true;
}
void dfs(int pos, int begin)
{if (pos > k){if (isprime(path))ret++;return;}for (int i = begin; i <= n; i++){path += a[i];dfs(pos + 1, i + 1);path -= a[i];}
}
int main()
{cin >> n >> k;for (int i = 1; i <= n; i++){cin >> a[i];}dfs(1, 1);cout << ret << endl;return 0;
}