Big-O Articles | Backend Study Lab

Algorithms Jul 1, 2026 4 min read

Prefix Sum Algorithm Explained

Learn prefix sums with Java examples, range-sum queries, subarray patterns, difference arrays, complexity, and when preprocessing is worth it.

Algorithms Jul 1, 2026 5 min read

Learn the sliding window algorithm pattern with Java examples, fixed windows, variable windows, two pointers, complexity, and common mistakes.

Algorithms Jul 1, 2026 5 min read

Learn the two pointers algorithm pattern with Java examples for sorted arrays, pairs, partitions, linked lists, complexity, and common mistakes.

Algorithms Jun 28, 2026 4 min read

Learn how binary search works, when it applies, common off-by-one mistakes, and how to implement iterative binary search in Java.

Algorithms Jun 28, 2026 4 min read

Learn common ways to solve top K elements problems with sorting, heaps, and Java PriorityQueue, including complexity tradeoffs.

Java May 10, 2026 6 min read

A practical reference for Java collection time complexity, including ArrayList, LinkedList, HashMap, TreeMap, HashSet, and PriorityQueue.

Algorithms Feb 4, 2026 4 min read

Learn Big-O notation with practical backend examples, including arrays, hash maps, sorting, nested loops, and database-like thinking.