Top K Frequent Elements

Difficulty

Medium

Question

Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.

Example 1:

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

Example 2:

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

Constraints:

1 <= nums.length <= 105
-104 <= nums[i] <= 104
k is in the range [1, the number of unique elements in the array].
It is guaranteed that the answer is unique.

Follow up:

Your algorithm's time complexity must be better than O(n log n), where n is the array's size.

Link

Top K Frequent Elements

Solution

Solution uses map of occurrences and min-heap of k-size to track top frequent elements.