Minimum Groups with Max Difference Constraint

Given an integer array, partition the array into the minimum number of groups such that the difference between any two elements in any group is no more than a given integer maxdiff. For example, given the array [3, 6, 1, 9] and maxdiff = 3, it should return 2 because the array can be partitioned into groups [1, 3] and [6, 9]. Example: Input: [3, 6, 1, 9], maxdiff = 3 Output: 2 Input: [1, 2, 3, 4, 5], maxdiff = 0 Output: 5 Example Input [3, 6, 1, 9], maxdiff=3 Output 2