Chocolate Distribution Problem

Given an array of n integers where each value represents number of chocolates in a packet. Each packet can have variable number of chocolates. There are m students, the task is to distribute chocolate packets such that:

1. Each student gets one packet.

2. The difference between the number of chocolates in packet with maximum chocolates and packet with minimum chocolates given to the students is minimum.

Examples:

Input : arr[] = {7, 3, 2, 4, 9, 12, 56} m = 3 Output: Minimum Difference is 2 We have seven packets of chocolates and we need to pick three packets for 3 students If we pick 2, 3 and 4, we get the minimum difference between maximum and minimum packet sizes.

Input : arr[] = {3, 4, 1, 9, 56, 7, 9, 12} m = 5 Output: Minimum Difference is 6 The set goes like 3,4,7,9,9 and the output is 9-3 = 6

Input : arr[] = {12, 4, 7, 9, 2, 23, 25, 41, 30, 40, 28, 42, 30, 44, 48, 43, 50} m = 7 Output: Minimum Difference is 10 We need to pick 7 packets. We pick 40, 41, 42, 44, 48, 43 and 50 to minimize difference between maximum and minimum.

class solution {
    public static int findMinDiff(int[] arr, int m) {
        int n = arr.length;
        if (m == 0 || n == 0)
            return 0;
        Arrays.sort(arr);
        if (n < m)
            return -1;
        int min = Integer.MAX_VALUE;
        for (int i = 0; i <= n - m; i++) {
            if (arr[i + m - 1] - arr[i] < min)
                min = arr[i + m - 1] - arr[i];
        }
        return min;
    }
}