由于题设中的区间长度为17，山的高度限定在0-100之间，所有可能的区间为0-17，1-18···83-100共84个，穷举算出最小值即可

#include<iostream>
#include<algorithm>
using namespace std;
const int N = 1005;
int arr[N];
int main() {
    int n;
    cin >> n;
    for (int i = 0;i < n;i++) cin >> arr[i];
    int cost = 0,ans = 1e9;
    int l = 0,r = 17;
    while (l <= 83) {
        for (int i = 0;i < n;i++) {
            if (arr[i] < l) {
                cost += (l - arr[i]) * (l - arr[i]);
            } 
            if (arr[i] > r) {
                cost += (arr[i] - r) * (arr[i] - r);
            }
        }
        ans = min(ans,cost);
        l++;
        r++;
        cost = 0;
    }
    cout << ans << endl;
}