[math][第二阶段-easy math][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

 

import java.util.Scanner;


public class Main {
	public static boolean judge(int n){
		int i;
		if(n==2)return true;
		for(i=2;i<Math.sqrt(n)+1;i++){
			if(n%i==0)
				return false;
		}
		return true;
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in = new Scanner(System.in);
		
		while(in.hasNext()){
		int n = in.nextInt();
		int i,sum=0;
		for(i=0;i<n;i++){
			int m = in.nextInt();
			if(judge(m))sum++;
		}
		System.out.println(sum);
		}
	}
}