Array Top K Frequent Elements LeetCode (top K frequent elements)

Given a non-empty array of integers, return the k most frequent elements.

Example 1:

• Input: nums = [1,1,1,2,2,3], k = 2
• Output: [1,2]

Example 2:

• Input: nums = [1], k = 1
• Output: [1]

NOTE:

• You may assume k is always valid, 1 ≤ k ≤ number of unique elements.
• Your algorithm's time complexity must be better than O(n log n), where n is the array's size.

This problem is also discussed in LeetCode, GeeksForGeeks (here and here) A collection of hundreds of interview questions and solutions are available in our blog at Interview Question Solutions

Solution: