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| Time Limit: 1000MS | Memory Limit: 65536K | |
| Total Submissions: 6033 | Accepted: 3351 |
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
老师给糖给 1 2号学生,然后接下来隔着一个学生给糖,隔着两个学生给糖,问一直这样下去,是否所有学生都会拿到糖?
找规律，判断 n是否为 2^k...快速判断 n是否为 2的指数幂的方法 n&n-1...
#include <stdio.h> #include <algorithm> #include <string.h> using namespace std; typedef long long LL; const int N = 1005; int main() { int n; while(scanf("%d",&n)!=EOF){ if((n&(n-1))==0) printf("YES\n"); else printf("NO\n"); } return 0; }
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原文地址：http://www.cnblogs.com/liyinggang/p/5967148.html
