P1247 取火柴游戏（异或理论）

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 5e5 + 5;
int n;
int a[maxn];
signed main(){
    //freopen("in","r",stdin);
    ios::sync_with_stdio(0);
    cin >> n;
    int tmp = 0;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        tmp ^= a[i];
    }
    if(tmp){
        for(int i = 1; i <= n; i++){
           if((a[i] ^ tmp) >= a[i])
               continue;
           cout << a[i] - (a[i] ^ tmp) << " " << i << endl;
           a[i] ^= tmp;
            break;
        }
        for(int i = 1; i <= n; i++)
            cout << a[i] << " ";
    }else cout << "lose\n";
    return 0;
}