Problem:
Score : 400 points

Problem Statement

You are given N integers; the i-th of them is A_i.
Find the maximum possible sum of the absolute differences between the adjacent elements after arranging these integers in a row in any order you like.

Constraints

2 \leq N \leq 10^5

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_N

Output

Print the maximum possible sum of the absolute differences between the adjacent elements after arranging the given integers in a row in any order you like.

Sample Input 1

5
6
8
1
2
3

Sample Output 1

21

When the integers are arranged as 3,8,1,6,2, the sum of the absolute differences between the adjacent elements is |3 - 8| + |8 - 1| + |1 - 6| + |6 - 2| = 21. This is the maximum possible sum.

Sample Input 2

6
3
1
4
1
5
9

Sample Output 2

25

Sample Input 3

3
5
5
1

Sample Output 3

8

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using static System.Console;

class Program
{
    public static void Main()
    {
	int n = int.Parse(ReadLine());
	int[] a = new int[n];
	for (int i = 0; i < n; i++)
	    a[i] = int.Parse(ReadLine());

	Array.Sort(a);

	int a1 = a[0], a2 = a[0];
	int cl = 1, cr = n-1;

	long ans = 0;
	int mode = 0; // 0,1 : right, 2, 3 : left
	int ct = 1;
	
	while (ct++ < n)
	{
	    int x;
	    if (mode < 2)
	    {
		x = a[cr--];
	    }
	    else
	    {
		x = a[cl++];
	    }

	    if ((mode&1) == 0)
	    {
		ans += Math.Abs(x-a1);
		a1 = x;
	    }
	    else
	    {
		ans += Math.Abs(x-a2);
		a2 = x;
	    }
	    mode = (mode + 1) & 3;
	}
	WriteLine(ans);
    }
}