View Code of Problem 4065

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <queue>
#include <vector>
using namespace std;
int main(void)
{
    vector<int> v;
    int n;
    cin >> n;
    for (int i = 0; i < n;i++){
        int a;
        cin >> a;
        v.push_back(a);
    }
    v.insert(v.begin(), 0);
    sort(v.rbegin(), v.rend());
    int cnt = 0;
    int sum = 0;
    for (auto a = v.begin(), b = v.end() - 1;a != b;){
        sum += (*a - *b) * (*a - *b);
        if(cnt % 2 == 0)
            b--;
        else
            a++;
        cnt++;
    }
    cout << sum << endl;
}