AcWing 892. stairs -Nim game

 

#include<iostream>
using namespace std;
int n;
int main() {
    cin>>n;
    int res=0;
    for(int i=1; i<=n; i++) {
        int x;
        cin>>x;
        if(i%2) res=res^x;//判断是不是奇数
    }
    if(res!=0) cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
}