Be the Winner

Be the Winner

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)

Total Submission(s): 63 Accepted Submission(s): 48

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

2
2 2
1
3

 

Sample Output

No
Yes

 

Source

ECJTU 2008 Autumn Contest

 

Recommend

lcy

 

/*
题意；n堆物品，谁拿最后一个谁输

初步思路：裸的尼姆博弈
*/
#include<bits/stdc++.h>
using namespace std;
int n;
int res,a;
int main(){
    // freopen("in.txt","r",stdin);
    int ca=0;
    while(scanf("%d",&n)!=EOF){
        res=0;
        int f=0;
        for(int i=0;i<n;i++){
            scanf("%d",&a);
            if(a>1) f=1;
            res^=a;
        }
        if(f) printf(res?"Yes\n":"No\n");
        else printf(n&1?"No\n":"Yes\n");
    }
    return 0;
}