HTMLify

class Solution:
    def findMinDiff(self, arr, m):
        if m == 0 or len(arr) == 0:
            return 0
        
        arr.sort()
        
        n = len(arr)
        if n < m:
            return -1
        
        min_diff = float('inf')
        
        for i in range(n - m + 1):
            current_diff = arr[i + m - 1] - arr[i]
            if current_diff < min_diff:
                min_diff = current_diff
                
        return min_diff