Problem:
Score : 500 points

Problem Statement

There are N children standing in a line from left to right. The activeness of the i-th child from the left is A_i.

You can rearrange these children just one time in any order you like.

When a child who originally occupies the x-th position from the left in the line moves to the y-th position from the left, that child earns A_x \times |x-y| happiness points.

Find the maximum total happiness points the children can earn.

Constraints

2 \leq N \leq 2000

1 \leq A_i \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N

Output

Print the maximum total happiness points the children can earn.

Sample Input 1

4
1 3 4 2

Sample Output 1

20

If we move the 1-st child from the left to the 3-rd position from the left, the 2-nd child to the 4-th position, the 3-rd child to the 1-st position, and the 4-th child to the 2-nd position, the children earns 1 \times |1-3|+3 \times |2-4|+4 \times |3-1|+2 \times |4-2|=20 happiness points in total.

Sample Input 2

6
5 5 6 1 1 1

Sample Output 2

58

Sample Input 3

6
8 6 9 1 2 1

Sample Output 3

85

Solution in Rust (1.42.0) (judge verdict: Accepted)

#![allow(unused_imports)]
use itertools::Itertools;
use proconio::{input, marker::*};
use std::cmp::*;
use std::collections::*;
use superslice::*;

fn main() {
    input! {
        n: usize,
        a: [i64; n],
    }

    let mut a = a.iter().zip(0..n).collect::<Vec<_>>();
    a.sort();
    a.reverse();

    let mut dp = vec![vec![0; n + 1]; n + 1];

    for l in 0..n {
        for r in 0..n {
            if l + r >= n {
                break;
            }

            let (v, i) = a[l + r];

            dp[l + 1][r] = max(dp[l + 1][r], dp[l][r] + v * (l as i64 - i as i64).abs());
            dp[l][r + 1] = max(
                dp[l][r + 1],
                dp[l][r] + v * (n as i64 - 1 - r as i64 - i as i64).abs(),
            );
        }
    }

    let mut ans = 0;

    for i in 0..n {
        ans = max(ans, dp[i][n - i]);
    }

    println!("{}", ans);
}