The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 days. Why not try and solve them ahead of time?
Foo Fizz Buzz Bar in Python in chars. Achievements Cheevos Holes Languages Medals Miscellaneous All Holes 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Multitap Input Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> ALGOL 68 ArkScript Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig 05AB1E APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> ALGOL 68 ArkScript Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig Experimental Language 05AB1E APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Hole All 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Multitap Input Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Experimental Hole Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Chars Time Submitted 561st Kasci 606 109 40ms 6 Dec 2021 561st aazuspan 606 109 12ms 27 Dec 2021 561st vigneshhari 606 109 18ms 18 Jan 2022 561st quasar098 606 109 12ms 16 Mar 2022 561st hippopotam00sehead 🇨🇦 606 109 11ms 11 Sep 2024 561st lgoeldner 606 109 10ms 15 Jan 2025 567th TheSmilingTurtle 600 110 11ms 14 May 2022 567th randomn4me 600 110 58ms 7 Oct 2022 567th rachitkeyal 600 110 11ms 9 Nov 2022 567th BlakeBleem 600 110 11ms 21 Apr 2023 567th anonymaew 600 110 12ms 2 Aug 2023 567th MisterrLuck 600 110 10ms 3 Sep 2023 567th cloudberry-DeaDev 600 110 12ms 19 Dec 2023 567th gracetyy 🇭🇰 600 110 9ms 2 Jul 2024 567th ebeinroth 600 110 10ms 6 Aug 2024 567th Alex-Huggett 🇬🇧 600 110 41ms 23 Oct 2024 567th ahmedshifathedataengineer 600 110 11ms 19 Sep 2025 578th mathb0y512 595 111 12ms 29 Nov 2022 578th BLD933 🇲🇦 595 111 11ms 1 Sep 2023 578th HelloYuiYui 595 111 11ms 31 Oct 2023 578th Igyeom 🇰🇷 595 111 18ms 5 Feb 2024 582nd LeeCamp 589 112 11ms 11 Dec 2021 582nd andrewgopher 589 112 11ms 25 Jun 2022 582nd avinashv 589 112 11ms 12 Nov 2022 582nd Webatron11 589 112 11ms 24 Nov 2022 582nd S-Ruban 589 112 9ms 25 Feb 2023 582nd Florian-Mt 589 112 11ms 26 Sep 2023 582nd sli-Lut 589 112 12ms 11 Oct 2023 582nd b20fuji 589 112 12ms 18 Oct 2023 582nd PyryL 🇫🇮 589 112 12ms 21 Aug 2024 591st ArmaanAS 584 113 19ms 28 Nov 2021 591st oomido 584 113 11ms 7 Sep 2022 591st DayDun 🇸🇪 584 113 13ms 21 Jan 2023 591st djtroyal 584 113 12ms 13 Feb 2023 591st msbranicky 584 113 18ms 5 Jul 2023 591st khavik 584 113 12ms 18 May 2024 591st MamoonUddin 584 113 11ms 3 Dec 2024 591st Hyperoplex145 584 113 12ms 10 Nov 2025 599th Andrey135296 579 114 12ms 3 Jan 2022 599th Liastrae 579 114 11ms 22 Aug 2022 599th Nicronmil 579 114 12ms 25 Nov 2022 599th aliberro39109 579 114 12ms 1 Sep 2025 603rd dzshn 574 115 18ms 17 Aug 2022 603rd dillon-duncando 574 115 11ms 5 Oct 2022 603rd tails618 574 115 18ms 1 Dec 2022 603rd Azearia 574 115 11ms 23 Oct 2023 603rd mishak-sys 574 115 11ms 24 Feb 2025 603rd WillowWispy 574 115 11ms 16 Mar 2025 603rd Cube14yt 574 115 17ms 12 Oct 2025 610th TobyBoyne 🇬🇧 569 116 12ms 28 Jan 2022 610th HallMatthew314 569 116 17ms 15 Sep 2022 610th Pena86 569 116 12ms 16 Sep 2022 610th pricemat 569 116 12ms 11 Oct 2023 610th cmccandless 569 116 12ms 16 Oct 2023 610th m42km 569 116 12ms 25 Oct 2023 610th nhausspiegel 569 116 12ms 11 Apr 2024 610th resoNathan 569 116 11ms 25 Apr 2024 618th hellomath010118 564 117 10ms 26 Nov 2021 618th pengu1n-master 564 117 12ms 10 Dec 2021 618th Roboprod 564 117 13ms 24 Aug 2022 618th roguh 🇬🇹 564 117 11ms 7 Jan 2024 618th Masttest 564 117 12ms 31 Jan 2024 618th smilesformiles3 564 117 11ms 12 Jun 2025 624th init-jay 559 118 66ms 10 Aug 2022 624th fenix-bear 559 118 11ms 6 Jul 2023 624th jameswmccarty 559 118 11ms 9 Oct 2024 624th Googolplexo 🇷🇺 559 118 12ms 22 hours ago 628th VilBoub 555 119 18ms 20 Apr 2022 628th julienlamoureux78 555 119 12ms 12 Aug 2022 628th za3k 555 119 12ms 12 Oct 2022 628th ozzypossie 555 119 12ms 24 May 2023 628th odelo 555 119 12ms 12 Oct 2023 628th rustykitty 🇺🇸 555 119 19ms 24 Oct 2025 634th nmgetahun 550 120 11ms 9 Dec 2022 634th Natz12 550 120 11ms 12 Jan 2023 634th AdamMorris377 550 120 11ms 22 Sep 2024 634th Mathrew2012 550 120 11ms 9 Nov 2024 634th Code-Coder-coder 550 120 11ms 11 Oct 2025 639th puffertron 545 121 10ms 31 Aug 2023 639th Loag 545 121 11ms 22 Sep 2024 First Prev 561–640 of 879 Next Last