试除法判定一个数是否为质数类似于这道题: 代码:
#include<bits/stdc++.h> using namespace std; int main() { cin >> n; for (int i = 2;i * i <= n;i ++) { if (n % i == 0) { cout << "no" << endl; return 0; } } cout << "yes" << endl; return 0; } // O(sqrt(n))