Chocolate Distribution Problem

You are given an array/list CHOCOLATES of size 'N', where each element represents the number of chocolates in a packet. Your task is to distribute these chocolates among 'M' students such that:

1. Each student receives at least one packet of chocolates.
2. The difference between the largest and smallest number of chocolates in the distributed packets is minimized.

Input:

 T: number of test cases 
 For each test case: 
 N M: two space-separated integers denoting the number of packets and number of students 
 CHOCOLATES: 'N' space-separated integers representing chocolates in each packet 

Output:

For each test case, print the minimum possible difference between the maximum and minimum number of chocolates in packets, distributed to students. 

Example:

 Input: 
T = 1 
N = 5, M = 3 
CHOCOLATES = [8, 11, 7, 15, 2] 
 Output: 
4 

Constraints:

• 1 <= T <= 50
• 2 <= M <= N <= 10^4
• 1 <= CHOCOLATES[i] <= 10^9

Note:

You are not required to print anything. Implement the given function to return the required result.