Solutions that include sorting are suboptimal - Sorting requires O(n log n) complexity, whether building a heap takes O(n) time complexity.
As we only need unordered subset of top K elements of an array, Min Heap can be used.

+1

This is what I was attempting but fell short. Very clever.

Please don't make an unnecessary copy of that array when you can achieve comparable readability without doing so. Sorry, but I would definitely not consider that solution best practice.

This is my first translation. If I've done anything wrong then tell me and I'll try to fix it :)
Just realised that the tests aren't done in random order.