algorithms

A JSConf 2014 talk visually breaking down algorithms behind everyday UI patterns, such as dropdown menus that vanish when the mouse drifts and picking the nearest target to the cursor. It shows how these are implemented in JavaScript.

A visualization and sonification of 15 sorting algorithms, from selection sort to bogo sort, run on shuffled integers in six minutes. Each algorithm gets a size and speed scaled to its complexity.

Andrei Alexandrescu's CppCon 2019 talk revisits sorting, showing how branchless tricks, hybrid strategies and a cost metric can speed up std::sort-style algorithms on modern hardware.

Tom Scott-style absurdist tour by Tom7 of SIGBOVIK chess projects: a tournament of 30 weird chess algorithms used to rate a color- and piece-blind chess program. Topics include mirrors, arithmetic encoding, perverted game tree search and a diluted Stockfish.

Lex Fridman interviews Donald Knuth about algorithms, complexity, The Art of Computer Programming, and his work habits. The conversation covers his approach to verifying algorithms and how he organises his time.

Chandler Carruth's CppCon 2014 talk on writing fast C++, explaining why data structure choice and memory layout matter more than clever algorithms. It covers why standard containers like unordered_map perform poorly on modern CPUs.

Glenn Vanderburg presents Cló, a Clojure library that reimplements TeX's core typesetting algorithms as composable functions. He shows what translating procedural, literate-programming code into functional form teaches.

A Technology Connections video essay arguing that algorithmic feeds make people passive about finding content, leading to complacency in how they seek information. It urges people to actively choose what they consume.

Moleman 2 is a feature-length documentary about the demoscene, tracing its rise from 1980s Commodore 64 culture to modern real-time art. It explains the algorithms and creative process behind demos and intros.

Psychologist Robert Epstein presents a Stanford EE380 colloquium on how internet algorithms such as search rankings can manipulate opinions, purchases and votes at massive scale. He also describes a new monitoring system for tracking such influence.

Lukas Eder's Devoxx talk on how modern cost-based SQL optimizers rewrite and plan queries in ways developers would not expect. It argues that declarative SQL, used well, can run complex queries very fast.

Guy Steele presents a small geometric problem and compares four computational approaches: a classic sequential solution and three parallel-friendly ones. Each is illustrated pictorially and with working code, weighing total work against time to solution.

Hungarian folk dancers from Sapientia University act out the quicksort algorithm step by step, with music. It is part of the AlgoRythmics series of sorting algorithms performed as dance.

A three-minute capture of SORTDEMO.BAS, the sorting visualization that shipped with QBasic. It animates insertion, bubble, heap, exchange, shell and quick sort with chiptune-like sound.

Reducible's visual walkthrough of the Fast Fourier Transform, motivated by polynomial multiplication. It shows how the FFT's key ideas can be discovered by asking the right questions.

Erik Demaine's MIT 6.006 lecture introducing dynamic programming through Fibonacci numbers and shortest paths. It covers memoization, subproblems and optimal substructure.

Martin Donald explains the Wave Function Collapse algorithm using Sudoku-like constraint solving and shows how he implemented it with Blender and Godot. It links demos and reference articles.

Bryan Cantrill presents the ARC (Adaptive Replacement Cache) paper by Megiddo and Modha at Papers We Love. He opens with a survey of caching strategies before digging into the self-tuning LRU/MFU design.

Jon Bentley walks through three implementations of Hoare's Quicksort, from a dozen-line C function to a series of systematic code transformations that make the program ever simpler and more powerful. It is a Google Tech Talk on code elegance and program derivation.

Edward Kmett's 2013 talk at Prezi in Budapest on succinct data structures, which store data in close to the information-theoretic minimum space while supporting fast queries. It ties together the research and walks through his Haskell succinct library.

Matt Parker follows the community effort to speed up his slow Wordle-solving code, which ended up running hundreds of millions of times faster. He walks through the techniques contributors used.

A one-minute clip from Barack Obama's 2008 Google visit in which Eric Schmidt asks him the most efficient way to sort a million 32-bit integers. Obama answers that bubble sort would be the wrong choice.

A short CGP Grey bonus video explaining the shortest-splitline algorithm, which draws electoral districts by repeatedly splitting a state along its shortest dividing line while balancing population. It is offered as a neutral, algorithmic fix for gerrymandering.

Martin Kleppmann's QCon London 2018 talk on keeping data consistent in distributed systems without a central leader. It surveys CRDT algorithms for syncing devices and collaborative editing over peer-to-peer networks.

Stephan T. Lavavej's CppCon 2019 talk on implementing floating-point to_chars and from_chars in Microsoft's C++ STL. It covers the history of float-string conversion and the algorithms that make it much faster.

Polylog explains how algorithms can be turned into circuits and encoded as satisfiability problems, which lets you effectively run them backwards. It uses this to motivate breaking RSA, general reductions to SAT, and what P vs NP is really asking.

Martin Kleppmann surveys current research on CRDTs, the algorithms for merging concurrent edits across offline replicas. He covers the hard parts such as rich text, moves and merge results that are technically correct but poor.

Tom Scott's Royal Institution discourse on science communication in the age of social media, how recommendation algorithms shape popularity, and why view counts can matter more than truth. It includes a segment on parasocial relationships.

Andrei Alexandrescu's ACCU 2016 talk previews material from his book on writing fast code, with a focus on optimization techniques such as sentinels and faster search.

Peter Shor tells the story of how he discovered Shor's Algorithm, from his early mathematics days to the quantum factoring breakthrough. It was recorded at MIT at the Physics of Computation conference.

Matt Kulukundis explains how Google designed SwissTable, a fast, cache-friendly hash table, step by step from std::unordered_map. The talk covers open addressing, SIMD probing and the tradeoffs of changing a fundamental data structure.

Python core developer Raymond Hettinger explains how Python's dictionary implementation evolved into the compact, ordered dict in Python 3.6. He uses pictures and small bits of pure Python, and covers key-sharing, compaction and versioning.

Juan Pedro Bolivar Puente explains immutable and persistent data structures in C++ and how they support value semantics. He presents the Immer library, rrb-trees, and a prototype text editor that opens a huge file instantly.

CGP Grey compares airplane boarding methods, based on an arXiv paper, and shows why the intuitive back-to-front approach is slow while random or outside-in boarding does better.

Dave Ackley demonstrates the Demon Horde Sort, an inherently robust sorting machine running in his Movable Feast Machine simulator. This is the uncut version with all details and side thoughts.

Donald Knuth's 2017 Christmas Tree Lecture at Stanford about a combinatorial geometry problem whose computed numbers matched a striking formula. He tells the story of the conjecture and its sequel.

A 2007 Google Tech Talk in which Cliff Click of Azul Systems presents a lock-free concurrent hash table that scales to 768 CPUs. He explains why it is correct by reasoning in a different way than usual happens-before and memory-order arguments.

A Dyalog demonstration of developing a Sudoku solver in APL, using an algorithm by Arthur Whitney with performance work by John Scholes. The narration steps through the array-oriented solution.

A feature-length Defunctland documentary on the history of Disney's FastPass and FastPass+ expedited queue systems. It covers how the systems evolved and how they were designed, with simulation of their effects on park lines.

Lee Byron of Facebook explains how persistent immutable data structures work and how to use them in React apps with Immutable.js. He covers memoization benefits and avoiding coupling through shared mutable state.