hdu---4994---Revenge of Nim

#include <cstdio>
#include <cstring>
#include <iostream>
#include <cmath>
#include<vector>
#include<queue>
#include<algorithm>

using namespace std;
typedef long long LL;

const int maxn=500009;
const int INF=0x3f3f3f3f;
const int mod=2009;

int main()
{
    int T;
    scanf("%d", &T);

    while(T--)
    {
        int n, num;
        scanf("%d", &n);

        int sign=0;
        for(int i=1; i<=n; i++)
        {
            scanf("%d", &num);
            if(num!=1 && !sign)
                sign=i;
        }
        ///!sign&&n%2判断如果每一堆都是1,n为奇数赢
        ///sign&&(sign-1)%2==0开头连续个1的个数是偶数才会赢，同时也包括没有1的情况
        if((!sign&&n%2) || (sign&&(sign-1)%2==0))
            puts("Yes");
        else
            puts("No");
    }
    return 0;
}