hdoj 2509 Be the Winner(尼姆博奕变形)



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

Be the Winner

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2170    Accepted Submission(s): 1177

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

#include<stdio.h>int main(){int N,i,j,sum,num;while(scanf("%d",&N)!=EOF){for(i=0,sum=0,num=0;i<N;i++)    {    scanf("%d",&j);    sum^=j;    if(j!=1)    num+=1;    }    if(num==0&&sum==0||num>0&&sum!=0)//SJ定理     printf("Yes\n");    else    printf("No\n");}return 0;}//SJ定理 //先手必胜当且仅当：  //（1）所有堆的石子数都为1且游戏的SG值为0；  //（2）有些堆的石子数大于1且游戏的SG值不为0。