[博弈]HDU 2509 Be the Winner

传送门：Be the Winner

Be the Winner

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1679    Accepted Submission(s): 902

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

 

Source

ECJTU 2008 Autumn Contest

解题报告：

Nim博弈，注意全是1的时候，特判。代码如下：

#include <stdio.h>int main(){    int t,sum,tmp,flag;    while(scanf("%d",&t)==1){        sum=flag=0;        for(int i=0;i<t;i++){            scanf("%d",&tmp);            sum^=tmp;            if(tmp!=1)                flag=1;        }        if(flag){            if(!sum)                printf("No\n");            else                printf("Yes\n");        }        else{            if(sum%2==0)                printf("Yes\n");            else                printf("No\n");        }    }    return 0;}