Recursion in Python: How Recursive Algorithms Actually Work

Recursion in Python: How Recursive Algorithms Actually Work

Recursion lets a function solve a problem by calling itself on a smaller version of that problem. This guide explains how recursive calls work, how Python’s call stack keeps track of them, why base cases matter, and how recursion affects time and space complexity. You’ll also see practical examples, common mistakes, recursion trees, and when a loop is the better choice.
Best, Average, and Worst-Case Time Complexity Explained

Best, Average, and Worst-Case Time Complexity Explained

Best-case complexity is an algorithm's performance on the most favorable input. Average case is its typical performance across realistic inputs. Worst case is its performance on the least favorable input. All three can be described using Big O notation, and interviewers usually expect worst case unless stated otherwise.