Alice and Bob

Alice and Bob

时间限制：1000 ms  |  内存限制：65535 KB

难度：2

描述

As we all know, math is very important,so we must learn math well.

Alice and Bob are good friends.Today Alice ask Bob to help her judge whether a number is perfect or not. Perfect number is a kind of number like this:

First, 1 and 3 are perfect number.

Then if a and b are perfect numbers, 2+ab+2a+2b is also a perfect number.

For example, 1 and 3 are perfect numbers,  so 2+3+2+6 = 13 is perfect number.

If Bob can't help Alice,  Alice will be sad and Bob will be much more sad. So Bob must solve the problem to maintain their friendship. Can you help Bob to solve the problem?

输入

It contains multiple test cases.
Each test case contains one line.
Each line contains an interger n, 1 <= n <= 10^9.

输出

For each test case, if n is a perfect number, output “YES”, otherwise output “NO”.

样例输入

1623

样例输出

YESNOYES

由2+ab+2a+2b=(a+2)*(b+2)-2可知，(perfect number+2)满足被（a+2）和(b+2)整除。而1+2=3，3+2=5，故对于输入的数进行/3、/5的操作直到不能继续，如果最后得1，表示这个数是perfect number

#include<stdio.h>int main(){    int n;    while(scanf("%d",&n)!=-1)    {         int k;         k=n+2;         while(k%3==0)         {             k=k/3;         }         while(k%5==0)         {             k=k/5;         }         if(k==1)         {             printf("YES\n");         }         else         {             printf("NO\n");         }    }}