codeforces 768 E 变形NIM博弈／手写sg函数

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <map>
#include <queue>
#include <vector>
#include <cstring>
#include <iomanip>
#include <set>
#include<ctime>
#include<unordered_map>
//CLOCKS_PER_SEC
#define se second
#define fi first
#define ll long long
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define Pii pair<int,int>
#define Pli pair<ll,int>
#define ull unsigned long long
#define pb push_back
#define fio ios::sync_with_stdio(false);cin.tie(0)
const int N=2e5+10;
const ull base=163;
const int INF=0x3f3f3f3f;
using namespace std;
int a[70];
int main(){
    int n;
    fio;
    cin>>n;
    for(int i=1;i<=60;i++){
        a[i]=a[i-1]+i;
    }
    int sg=0;
    for(int i=1;i<=n;i++){
        int x;
        cin>>x;
        for(int j=1;j<=60;j++){
            if(a[j]>x){
                sg^=(j-1);
                break;
            }
        }
    }
    if(sg==0){
        cout<<"YES";
    }
    else cout<<"NO";
    return 0;
}