poj 3372 Candy Distribution

Description

N children standing in circle who are numbered 1 through N clockwise are waiting their candies. Their teacher distributes the candies by in the following way:

First the teacher gives child No.1 and No.2 a candy each. Then he walks clockwise along the circle, skipping one child (child No.3) and giving the next one (child No.4) a candy. And then he goes on his walk, skipping two children (child No.5 and No.6) and giving the next one (child No.7) a candy. And so on.

Now you have to tell the teacher whether all the children will get at least one candy?

Input

The input consists of several data sets, each containing a positive integer N (2 ≤ N ≤ 1,000,000,000).

Output

For each data set the output should be either "YES" or "NO".

Sample Input

23 4

Sample Output

YESNOYES

这是一道找规律题，又规律可以寻找的，自己摸拟几组数据，会发现满足的只有满足2的幂就可以满足。只有判断这个数是否为2的幂即可。

今天无意间看见一个这样一个算式：（n&(n-1)）这个表达式能确定一个数是否为2的幂。这非常简单又非常快的表达出来！

代码：

#include<stdio.h>int main(){    int n;    while(~scanf("%d",&n)){        if(n>0&&(n&(n-1))==0)            printf("YES\n");        else            printf("NO\n");    }return 0;}