Last-In-First-Out structures powering undo systems and expression parsing.

Theory & Description

A stack is a Last-In-First-Out (LIFO) data structure where elements are added and removed from the same end, called the top. Think of it like a stack of plates: you can only add or remove the top plate. Stacks are fundamental to function call management, expression evaluation, backtracking algorithms, and undo mechanisms in software.

Common Use Cases

  • Function call stack and recursion
  • Expression evaluation and syntax parsing
  • Undo/Redo operations in editors
  • Browser back/forward navigation

Complexity Cheat Sheet

OperationAverageWorst
AccessO(n)O(n)
SearchO(n)O(n)
PushO(1)O(1)
PopO(1)O(1)
Space ComplexityO(n)

Interactive Visualization

Interactive Visualization

An interactive playground for Stacks will appear here. Insert elements, step through operations, and watch the data structure update in real time.