ChocolateDistribution.cpp

 long long findMinDiff(vector<long long> a, long long n, long long m){
    //code
       sort(a.begin(),a.end());  
       long long int mini = INT_MAX; 
       int i = 0; 
       int j = m-1; 
       while(j < n){
           long long int diff = a[j]- a[i]; 
           mini = min(mini , diff); 
           i++, j++; 
       }
       return mini;
    }   

/*
Given an array A[ ] of positive integers of size N, where each value represents the number of chocolates in a packet. Each packet can have a variable number of chocolates. There are M students, the task is to distribute chocolate packets among M students such that :
1. Each student gets exactly one packet.
2. The difference between maximum number of chocolates given to a student and minimum number of chocolates given to a student is minimum.

Example 1:

Input:
N = 8, M = 5
A = {3, 4, 1, 9, 56, 7, 9, 12}
Output: 6
Explanation: The minimum difference between maximum chocolates and minimum chocolates is 9 - 3 = 6 by choosing following M packets :{3, 4, 9, 7, 9}.
Example 2:

Input:
N = 7, M = 3
A = {7, 3, 2, 4, 9, 12, 56}
Output: 2
Explanation: The minimum difference between maximum chocolates and minimum chocolates is 4 - 2 = 2 by choosing following M packets :{3, 2, 4}.
Your Task:
You don't need to take any input or print anything. Your task is to complete the function findMinDiff() which takes array A[ ], N and M as input parameters and returns the minimum possible difference between maximum number of chocolates given to a student and minimum number of chocolates given to a student.

Expected Time Complexity: O(N*Log(N))
Expected Auxiliary Space: O(1)

Constraints:
1 ≤ T ≤ 100
1 ≤ N ≤ 105
1 ≤ Ai ≤ 109
1 ≤ M ≤ N
*/