Java:

import java.util.Scanner;

public class S7_02 {
	static int n, num;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		while (n-- > 0) {
			num = sc.nextInt();
			f();
		}
	}

	static void f() {
		if (num == 1) {
			System.out.println("No");
			return;
		}
		boolean ok = false;
		for (int i = 2; i < Math.sqrt(num); i++) {
			if (num % i == 0) {
				ok = true;
				break;
			}
		}
		if (ok) {
			System.out.println("No");
		} else {
			System.out.println("Yes");
		}
	}
}

C++:

#include<iostream>
#include<cmath>
using namespace std;


int main(){
	int n,sq,flag;
	unsigned int x;
	cin>>n;
	while(n--){
		cin>>x;
		sq=sqrt(x);
		flag=1;
		if(x==1){
			cout<<"No"<<endl;
			continue;
		}
		for(int i=2;i<=sq;i++){
			if(x%i==0){
				flag=0;
				break;
			}
		}
		if(flag){
			cout<<"Yes"<<endl;
		}
		else cout<<"No"<<endl;
		
	}
	return 0;
}