Introduction to Top K Elements

About the pattern

The top k elements pattern is an important technique in coding that helps us efficiently find a specific number of elements, known as $k$, from a set of data. This is particularly useful when we’re tasked with identifying the largest, smallest, or most/least frequent elements within an unsorted collection.

To solve tasks like these, one might think to sort the entire collection first, which takes $O(n \log(n))$ time, and then select the top k elements, taking additional $O(k)$ ...