HDU2509 Be The Winner

Posted 2021-02-06 songorz

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). 

InputYou 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. 
OutputIf a winning strategies can be found, print a single line with "Yes", otherwise print "No". 
Sample Input

2
2 2
1
3

Sample Output

No
Yes
题解：考虑全为一的情况
参考代码：

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 int n,ans,val,cnt;
 4 int main() 
 5 {
 6     while(~scanf("%d",&n))
 7     {
 8         ans=cnt=0;
 9         for(int i=1;i<=n;++i){ scanf("%d",&val),ans^=val;if(val>1) cnt++; }
10         if((!ans&&cnt>1)||(ans&&!cnt)) puts("No");
11         else puts("Yes");
12     } 
13     
14     return 0;
15 }

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