ZOJ 2723

G - Semi-Prime
Time Limit:2000MS    Memory Limit:65536KB    64bit IO Format:%lld & %llu
Submit Status Practice ZOJ 2723

Description

Prime Number Definition
An integer greater than one is called a prime number if its only positive divisors (factors) are one and itself. For instance, 2, 11, 67, 89 are prime numbers but 8, 20, 27 are not.

Semi-Prime Number Definition
An integer greater than one is called a semi-prime number if it can be decompounded to TWO prime numbers. For example, 6 is a semi-prime number but 12 is not.

Your task is just to determinate whether a given number is a semi-prime number.

Input

There are several test cases in the input. Each case contains a single integer N (2 <= N <= 1,000,000)

Output

One line with a single integer for each case. If the number is a semi-prime number, then output "Yes", otherwise "No".

Sample Input

3
4
6
12

Sample Output

No
Yes
Yes
No


借鉴的以为女神链接的代码:

#include<iostream>
#include<cstdio>
using namespace std;
int primer[1000005]={0,0};
int main()
{
    for(int i=2;i<=1000000;i++)
        primer[i]=i;
    for(int i=2;i<500000;i++)
    {
        if(primer[i])
        {
            for(int j=2;j*i<500000;j++)
                primer[i*j]=0;
        }
    }
    int n,m,t;
    while(~scanf("%d",&n))
    {
        m=t=0;
        while(n!=1)
        {
            if(primer[m])
            {
                while(n%primer[m]==0)//判断是否是两个素数的乘积
                {
                    n=n/primer[m];
                    t++;
                }
            }
            m++;
        }
        if(t==2)
            cout<<"Yes"<<endl;
        else
            cout<<"No"<<endl;
    }
}


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