HDU-2138 How many prime numbers

Problem Description
Give you a lot of positive integers, just to find out how many prime numbers there are.

Input
There are a lot of cases. In each case, there is an integer N representing the number of integers to find. Each integer won’t exceed 32-bit signed integer, and each of them won’t be less than 2.

Output
For each case, print the number of prime numbers you have found out.

Sample Input
3
2 3 4

Sample Output
2

简单的求素数个数题 ：

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <iomanip>
#include <string>
#include <set>
#include <map>
#include <queue> 
#include <stack>
#include <vector>
#include <algorithm>
#include <sstream> 
#include <cstring>
using namespace std;

bool judge(int x)
{
    for(int i=2;i<=sqrt(x);i++)
    {
        if(x%i==0)
            return true;
    }
    return false;
} 

int main()
{
    int n,t;
    while(cin>>n)
    {
        int ans=0;
        while(n--)
        {
            cin>>t;
            if( judge(t)==false )
                ans++;
        }
        cout<<ans<<endl;
    }
    return 0;
}