#include <bits/stdc++.h>
using namespace std;
typedef long long LL;

int main() {
    int n;cin >> n;
    LL a[n] = { 0 };
    for (int i = 0;i < n;i++) {
        cin >> a[i];
        if (a[i] > a[0])swap(a[i], a[0]);
    }
    //按照差值最大值排序
    for (int i = 0;i < n - 1;i++) {
        int t = abs(a[i + 1] - a[i]);
        for (int j = i + 1;j < n;j++) {
            if (abs(a[j] - a[i]) > t) { swap(a[j], a[i + 1]);t = abs(a[i + 1] - a[i]); }
        }
    }
    // for (int i = 0;i < n;i++)cout << a[i] << ' ';
    // cout << endl;
    LL sum = a[0] * a[0];
    for (int i = 0;i < n - 1;i++)sum += (a[i + 1] - a[i]) * (a[i + 1] - a[i]);
    cout << sum;
}

我看大家似乎都用的顺序然后左右指针，此处给出一个比较容易理解的算法，效率不高，但勉强AC