Interactive Coding Challenges

---
name: interactive-coding-challenges
description: >
  120+ interactive coding challenges in Jupyter Notebooks covering data structures,
  algorithms, system design and OOP for interview prep. USE FOR: coding challenges,
  algorithm practice, data structures interview, leetcode style problems, DSA practice,
  array problems, linked list, graph algorithms, dynamic programming, sorting algorithms,
  bit manipulation, system design interview, OOP design, big-O complexity, technical interview prep.
kind: reference
category: dev/learning
repo: https://github.com/donnemartin/interactive-coding-challenges
tags: [algorithms, data-structures, interviews, python, jupyter]
status: active
---

# Interactive Coding Challenges

> 120+ challenges in Jupyter Notebooks with solutions, unit tests, and Big-O analysis.

## Categories

| Category | Count | Key Topics |
|----------|-------|------------|
| Arrays & Strings | 10 | two-sum, anagram, reverse, rotation, compression |
| Linked Lists | 8 | reverse, cycle detect, merge, nth-from-end |
| Stacks & Queues | 8 | min-stack, queue-via-stacks, balanced parens |
| Graphs & Trees | 21 | BFS, DFS, BST validate, LCA, trie, shortest path |
| Sorting | 10 | merge, quick, heap, radix, counting sort |
| Recursion & DP | 17 | fibonacci, knapsack, coin change, LCS |
| Math & Probability | 6 | prime sieve, power set, probability |
| Bit Manipulation | 8 | XOR tricks, count bits, power of 2 |
| System Design | 8 | URL shortener, pastebin, Twitter, Instagram |
| OOP Design | 8 | deck of cards, parking lot, call center, chess |

## Implementations Included

**Data Structures (9):** LinkedList, Stack, Queue, BinarySearchTree, Graph, MinHeap, Trie, PriorityQueue, HashMap

**Algorithms (15):** Selection, Insertion, Quick, Merge, Radix sort; DFS, BFS, Dijkstra; Knapsack (0/1 + Unbounded); Sieve of Eratosthenes

## Each Challenge Contains
- Problem statement + constraints
- Unit tests (general + edge cases)
- Skeleton code to fill
- Reference solution with Big-O analysis

## Setup
```bash
git clone https://github.com/donnemartin/interactive-coding-challenges
cd interactive-coding-challenges
pip install jupyter
jupyter notebook
# Open *_challenge.ipynb -> solve -> check *_solution.ipynb
```