Python Interview Question 42 - Given an integer array `nums` and an integer `k`, return `true` if
*Explanation:* `nums[2]` and `nums[3]` are both `1`, and the indices difference is `3 - 2 = 1`, which is equal to `k`.
*Output:* `True`
Scenario 3
*Input:* `nums = [1, 2, 3, 1, 2, 3]`, `k = 2`
*Explanation:* There are no pairs of duplicate elements where the indices difference is less than or equal to `k`.
*Output:* `False`
Explanation
Dictionary `index_map`
This dictionary keeps track of the last seen index of each element in the array.
Iteration over the Array
We iterate over the array using `enumerate()` to get both the index `i` and the value `num` at each step.
If the element `num` has been seen before (i.e., it exists in `index_map`), we check if the difference between the current index `i` and the last seen index `index_map[num]` is less than or equal to `k`.
If the condition is satisfied, the function returns `True`.
Updating the Dictionary
Whether or not a duplicate is found, we update the dictionary with the current index of the element.
Returning the Result
If no such pair of indices is found during the iteration, the function returns `False`.