栗酱的异或和

 

 不进位加法

要写成 < ,不是 <=

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 1e5 + 5;
int t,n,k;
int a[maxn],ans;
signed main(){
    //freopen("in","r",stdin);
    ios::sync_with_stdio(0);
    cin >> t;
    while(t--){
        cin >> n >> k;
        ans = 0;
        for(int i = 1; i <= n; i++){
            cin >> a[i];
            ans ^= a[i];
        }
        if((ans ^ a[k]) < a[k]) cout << "Yes" << endl;
        else cout << "No" << endl;
    }
    return 0;
}

 

来源：https://www.cnblogs.com/xcfxcf/p/12610133.html