HDU-2509-Be the Winner【nimm】

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=2509

Be the Winner

Problem Description

Let's consider m apples divided into n groups. Each group contains no more than 100 apples, arranged in a line. You can take any number of consecutive apples at one time.
For example "@@@" can be turned into "@@" or "@" or "@ @"(two piles). two people get apples one after another and the one who takes the last is 
the loser. Fra wants to know in which situations he can win by playing strategies (that is, no matter what action the rival takes, fra will win).

 

Input

You will be given several cases. Each test case begins with a single number n (1 <= n <= 100), followed by a line with n numbers, the number of apples in each pile. There is a blank line between cases.

 

Output

If a winning strategies can be found, print a single line with "Yes", otherwise print "No".

 

Sample Input

22 213

 

Sample Output

NoYes

 

题目 分析： （和hdu-1907一样）

最后取完者为负。
1）如果全是1的时候，特判，奇数则输。
2）否则 nim博弈，求异或值，为0则输。

#include<iostream>using namespace std;int main(){int n,i,x;while(cin>>n){int ans=0,flag=0;for(i=1;i<=n;i++){cin>>x;ans^=x;if(x!=1)flag=1;}if(flag){if(ans)cout<<"Yes"<<endl;elsecout<<"No"<<endl;}else{if(n%2)cout<<"No"<<endl;elsecout<<"Yes"<<endl;}}return 0;}