project Euler problem 10

/** * Created by Administrator on 2015/5/10. */public class E10 {    //判断一个数是否是质数    public  static boolean isPrime(int x)    {        boolean isPrime=true;        for(int i=2;i<=Math.sqrt(x);i++)            if(x%i==0)            {                isPrime=false;                break;            }        return isPrime;    }    public static void main(String[] args) {        long sum=0;//注意用long 否者会越界        for(int i=2;i<2000000;i++)            if(isPrime(i))                sum+=i;        System.out.println(sum);    }}