Stack
Last in, first out — matching brackets, undo, nested structure, and expression evaluation.
This topic is part of Pro.
Free covers the C and Python courses, the first three DSA topics, the opening system design lessons and the beginner AI lessons, all with the full coach. Pro opens the rest of the library in the FollowtheDamnCode app.
What is in it
- 1How stacks workPush, pop, and peek at one end — built on a dynamic array, all O(1). Pro
- 2Matching bracketsPush every opener; every closer must match the most recent unclosed opener. Pro
- 3Min stack and stack designAnswer "what's the minimum?" in O(1) by storing it alongside each item. Pro
- 4Evaluating expressionsReverse Polish notation in one stack pass, and how calculators handle precedence and brackets. Pro