Leetcode - Top K Frequent Elements

Question

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

Ideas

• Use the starting array and a hashmap to store frequent elements
• Use a linear pass to count frequencies in mapping
• Sort map by value in reverse (this part is just python semantics)
• Slice values array from mapping and return the first k elements

Solution

This solution should in theory by asymptotically faster but in practice is slower due to python fuckery.

The actual optimized solution uses a min-heap where you just pop the min heap k times, append to a list and sent it.