接接接水问题

#include <bits/stdc++.h>
using namespace std;
bool cmp(int x,int y){
    return x < y;
}
int main(){
    int a[1010] = {0};
    int n;
    double sum = 0.00;
    cin >> n;
    for(int i = 0;i < n;i++){
        cin >> a[i];
    }
    sort(a,a + n,cmp);
    for(int i = 0;i < n;i++){
       sum += a[i] * (n - i);
    }
    cout << sum;
    return 0;
}