Two Sets

其實主要是在考貪婪演算法

但比較需要注意的是要用
unordered_set，會比較快

#include <bits/stdc++.h>
#define io ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
typedef long long ll;

int i;
vector<int> ans, li;
unordered_set<int> st;

int main(){ io;

    ll n, tot=0, i, half=0,cnt=0;
    cin >> n;

    for (i=1; i<=n ; i++) tot+=i;

    if (tot%2!=0){
        cout << "NO";
        return 0; //exit()
    }

    cout <<"YES"<< "\n";

    half = tot/2;

    for (i=n;i>0;i--){
        if (cnt+i <= half){
            ans.push_back(i);
            st.insert(i);
            cnt+=i;
        }
    }

    cout << ans.size()<< "\n";
    for (auto i :ans) cout << i << " ";

    for  (i=n;i>0;i--){
        if (!st.count(i)){
            li.push_back(i);
        }
    }

    cout << "\n" << li.size()<< "\n";
    for (auto x : li) {
        cout << x << ' ';
    }
}