Warning: Copying and pasting code from this cheat sheet for a programming competition will cause you to fail the plagiarism detector.

This cheat sheet contains concise implementations of common data structures and algorithms (DS&As) in Python. Its purpose is to give you a short list of DS&As that are worth memorizing because they are frequently used, yet most people struggle with them. I have excluded DS&As that most computer science graduates can implement with very little thought, such as tree traversals.

• Quickselect
• Radix Sort

• Index of First True

• All Nearest Smaller Values
• String Parsing

• Single Number

• Longest Common Subsequence
• Knapsack Problem
• Best Time to Buy and Sell Stock
• Matrix Chain Multiplication

• Djikstra's Algorithm
• Bellman-Ford Algorithm
• Floyd-Warshall Algorithm

• Fast O(n) Tricks
• 2-Line Memoization