题面:https://www.luogu.org/problem/P2197

本题的解法是把nim游戏看做是有向图游戏用SG函数来解的.

Code:
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

int T,n,m,x,f[10100],a[10010],sg[100010];
bool vis[100010];

void getSG(int n)
{
    memset(sg,0,sizeof(sg));
    for (int i=1; i<=n; i++)
    {
        memset(vis,0,sizeof(vis));
        for (int j=0; f[j]<=i; j++)
            vis[sg[i-f[j]]]=1;
        for (int j=0; j<=n; j++)
            if (!vis[j])
            {
                sg[i]=j; break;
            }
    }
}

int main()
{
    for (int i=1; i<=10001; i++) f[i]=i;
    getSG(10000);
    scanf("%d",&T);
    while (T--)
    {
        scanf("%d",&n);
        int ans=0;
        for (int i=1; i<=n; i++)
        {
            scanf("%d",&a[i]);
            ans^=a[i];
        }
        if (ans) printf("Yes\n");
        else printf("No\n"); 
    }
    return 0;
}