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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdlib.h>
#include <stdio.h>
int compare(const void *a,const void *b){
    if(*(int *)a>*(int*)b)return 1;
    return -1;
}
int main()
{   int n;
    scanf("%d",&n);
    int a[n];
    for(int i=0;i<n;i++){
        scanf("%d",&a[i]);
    }
    qsort(a,n,sizeof(int),compare);
    /*for(int i=0;i<n;i++){
        printf("%d ",a[i]);
    }printf("\n");
    */if(n==3){
        printf("%d",(abs(a[0]-a[1])+abs(a[0]-a[2]))>(abs(a[2]-a[1])+abs(a[2]-a[0]))?(abs(a[0]-a[1])+abs(a[0]-a[2])):(abs(a[2]-a[1])+abs(a[2]-a[0])));
        return 0;
    }
    int arr[n],flag=0,l=0,r=n-1;
    for(int i=0;i<n;i++)arr[i]=0;
    arr[0]=a[n/2];
    for(int i=1;i<n;i++){
        
        if(i%2==0){
            if(a[l]==arr[0]&&flag==0){
                l++;
                flag++;
            }
            arr[i]=a[l];
            l++;
        }else{
            if(a[r]==arr[0]&&flag==0){
                r--;
                flag++;
            }
            arr[i]=a[r];
            r--;
        }
    }
    /*for(int i=0;i<n;i++){
            printf("%d ",arr[i]);
        }
        printf("\n");
    */long long ans1=0;
    for(int i=0;i<n-1;i++){
        ans1+=abs(arr[i]-arr[i+1]);
    }
    for(int i=1;i<n;i++){
        if(i%2==0){
            if(a[r]==arr[0]&&flag==0){
                r--;
                flag++;
            }
            arr[i]=a[r];
            r--;
        }else{
            if(a[l]==arr[0]&&flag==0){
                l++;
                flag++;
            }
            arr[i]=a[l];
            l++;
        }
    }
    
    /*for(int i=0;i<n;i++){
            printf("%d ",arr[i]);
        }
        printf("\n");
        */long long ans2=0;
    for(int i=0;i<n-1;i++){
        ans2+=abs(arr[i]-arr[i+1]);
    }
    
    printf("%lld",ans1>ans2?ans1:ans2);

    return 0;
}