Topic
Coding Interview
Learn Coding Interview as a connected topic across chapters, concepts, simulations, and interview reasoning.
10 Concepts16 Articles4h 40m
Overview
Learn Coding Interview as a connected topic across chapters, concepts, simulations, and interview reasoning.
How this topic helps
Algorithms
Data Structures
Java
Heaps
Learning Path in this Topic
Series that contain articles from Coding Interview. Select a path to filter the article list.
Articles
16 matched articles
Article 1Big O Notation Explained: Time Complexity, Space Complexity, and Why They Matter in InterviewsTLDR: Big O notation describes how an algorithm's resource usage grows as input size grows — not how fast it runs on your laptop. Learn to identify the 7 complexity classes (O(1) through O(n!)), deriv34 min
Article 2Two Pointer Technique: Solving Pair and Partition Problems in O(n)TLDR: Place one pointer at the start and one at the end of a sorted array. Move them toward each other based on a comparison condition. Every classic pair/partition problem that naively runs in O(n²) 16 min
Article 3Tries (Prefix Trees): The Data Structure Behind AutocompleteTLDR: A Trie stores strings character by character in a tree, so every string sharing a common prefix shares those nodes. Insert and search are O(L) where L is the word length. Tries beat HashMaps on 17 min
Article 4Sliding Window Technique: From O(n·k) Scans to O(n) in One PassTLDR: Instead of recomputing a subarray aggregate from scratch on every shift, maintain it incrementally — add the incoming element, remove the outgoing element. For a fixed window this costs O(1) per16 min
Article 5Merge Intervals Pattern: Solve Scheduling Problems with Sort and SweepTLDR: Sort intervals by start time, then sweep left-to-right and merge any interval whose start ≤ the current running end. O(n log n) time, O(n) space. One pattern — three interview problems solved.
13 minArticle 6In-Place Reversal of a Linked List: The 3-Pointer Dance Every Interviewer ExpectsTLDR: Reversing a linked list in O(1) space requires three pointers — prev, curr, and next. Each step: save next, flip curr.next to point backward, advance both prev and curr. Learn this once and you 16 minPage 1 of 3