Maximise-Function-MAXFUN

/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;

/* Name of the class has to be "Main" only if the class is public. */
class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner s = new Scanner(System.in);
		int TC = s.nextInt();
		while(TC-->0){
		    long n = s.nextLong();
		    long[] a = new long[(int)n];
		    for(int i=0;i<a.length;i++){
		        a[i] = s.nextLong();
		    }
		    
		    long small = a[0];
		    for(int i=0;i<n;i++){
		        if(small>a[i]){
		            small = a[i];
		        }
		    }
		    //System.out.println(small);
		    long big=a[0];
		    for(int i=0;i<n;i++){
		        if(big<a[i]){
		            big = a[i];
		        }
		    }
		    //System.out.println(big);
		    
		    long ans = 2*(big-small);
		    System.out.println(ans);
		}// your code goes here
	}
	
	
}