11364 - Parking

import java.util.Arrays;
import java.util.Scanner;

class Another {
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        int testCases = scanner.nextInt();
        while (testCases-- > 0) {
            int shops = scanner.nextInt();
            int[] nums = new int[shops];
            for (int i=0;i<shops;i++) {
                nums[i] = scanner.nextInt();
            }
            Arrays.sort(nums);
            int dist = 0;
            for (int i=0;i<nums.length-1;i++) {
                dist += (nums[i+1]-nums[i]);
            }

            System.out.println(dist*2);
        }
    }


}