Interview Q&A / Data Structures & Algorithms
Data Structures & Algorithms interview questions
Arrays, linked lists, hashing, trees and patterns, with line-by-line code and complexity.
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- What is counting sort and when can it beat O(n log n)?
Counting sort counts how many times each value appears in a small integer range, then rebuilds the array from those counts. It runs in O(n + k) time for values in 0..k, so it beats comparison sorts when k is small.
IntermediateQuick answerCoding1 min read