Candy Distribution_找规律

Posted 2020-08-06 阿宝的锅锅

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 6012		Accepted: 3341

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

2
3 
4

Sample Output

YES
NO
YES

 

 

【思路】找规律，是2的指数输出yes否则no

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int main()
{
    long long n;
    while(~scanf("%lld",&n))
    {
       while(n)
       {
           if(n&1) break;//二进制数最右位为1时，若n为1，则为2的指数，否则不能除2了也要退出
           n>>=1;//相当于每次除2

       }
       if(n==1) printf("YES\n");
       else printf("NO\n");
    }
    return 0;
}