The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 2 days. Why not try and solve them ahead of time?
12 Days of Christmas 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 801st JasonRaubenheimer 351 542 10ms 25 Nov 2023 801st smothest 351 542 10ms 29 Dec 2023 801st ComputerKWasTaken 🇺🇸 351 542 10ms 31 May 2024 801st MiLk 351 542 13ms 19 Feb 2025 805th derekthatcher 350 543 10ms 24 Sep 2020 805th goolygong 350 543 10ms 20 Nov 2020 805th shinylego 350 543 11ms 19 Oct 2022 805th EthanGrant1 350 543 10ms 29 Dec 2022 805th tlucanti 🇷🇺 350 543 9ms 8 Jan 2024 805th jasonho2582001 350 543 10ms 28 Jun 2024 811th KiwiKoder0123 349 544 9ms 4 Jul 2019 811th Guptacos 349 544 10ms 2 Aug 2020 811th Pargolo 349 544 10ms 7 Oct 2021 811th humz2k 349 544 10ms 5 Jul 2022 811th AharonSambol 349 544 16ms 18 Aug 2023 811th AthiraPillai123 349 544 9ms 4 Jan 2024 811th multikatt 349 544 9ms 13 Jan 2026 811th davidludwik2370 349 544 10ms 21 days ago 819th dzshn 349 545 10ms 25 Nov 2020 819th jellybro99 349 545 9ms 15 Oct 2021 819th StoverGitHub 349 545 11ms 16 Jun 2022 819th Bananapants22 349 545 9ms 15 Aug 2022 819th bedwards 349 545 10ms 13 Jan 2025 824th llysnafedd 348 546 10ms 28 Aug 2020 824th alexstarosta 348 546 10ms 27 Jun 2024 824th kyleyarwood 348 546 9ms 4 Oct 2024 824th jwfiredragon 348 546 11ms 15 May 2025 828th smf0x10 347 547 10ms 3 Oct 2021 828th Eilonlif 🇮🇱 347 547 10ms 25 Dec 2022 828th b20fuji 347 547 10ms 18 Oct 2023 828th Amy-Checcllo 347 547 9ms 22 Sep 2024 828th GeorgeStatho 347 547 11ms 5 Aug 2025 833rd DylanScottCarroll 347 548 10ms 8 Nov 2021 833rd RubiksImplosion 347 548 10ms 4 Dec 2022 833rd felixcroc 347 548 11ms 1 Apr 2023 833rd epic-programmer-guy 347 548 10ms 29 Dec 2023 833rd MassimoParisi 347 548 16ms 24 Sep 2024 833rd Shotokhan 347 548 10ms 15 Sep 2025 833rd Evytag 🇫🇷 347 548 10ms 9 Oct 2025 840th afyber 346 549 9ms 26 Jun 2019 840th my1e5 346 549 9ms 29 Nov 2021 840th oakesy 346 549 10ms 19 May 2024 840th CyberTapir 346 549 10ms 30 Aug 2024 840th martindotexe 🇳🇴 346 549 17ms 15 Feb 2025 840th shawncrabtree 346 549 10ms 21 Jun 2025 840th Sharrrkkk 346 549 10ms 21 Jul 2025 847th Esterfox610 345 550 10ms 17 Aug 2022 847th llama1024 345 550 10ms 5 Dec 2022 847th lorienaquarius 345 550 10ms 31 Dec 2023 850th eoinfennessy 345 551 10ms 21 Jul 2021 850th micah-weitzman 345 551 10ms 27 Jul 2021 850th mehekj 345 551 10ms 29 Jul 2021 850th No-Jons 345 551 9ms 23 May 2022 854th Parapet128 344 552 9ms 17 Jan 2019 854th dillon-duncando 344 552 10ms 19 Dec 2021 854th nmougino 🇫🇷 344 552 17ms 31 May 2022 854th Vaibhav0460 344 552 10ms 16 Feb 2024 854th navier-1 344 552 10ms 15 Sep 2025 854th kasarino 344 552 10ms 30 Nov 2025 860th aazuspan 344 553 10ms 24 Nov 2021 860th leeyonjae 344 553 11ms 10 Dec 2023 860th jjkochan2 344 553 9ms 17 Jan 2025 863rd carsonsyberg 343 554 11ms 9 May 2022 864th Alexander-Francis 342 555 10ms 10 Jul 2019 864th itiievskyi 🇺🇦 342 555 10ms 10 Aug 2020 864th KasperKivimaeki 🇫🇮 342 555 10ms 20 Nov 2025 864th pingpwn 342 555 10ms 14 Feb 2026 868th dddthedark 342 556 10ms 21 Jun 2019 868th ejerrard 342 556 10ms 27 Aug 2020 868th robertovers 342 556 14ms 29 Sep 2023 868th imnotAlexKnight 342 556 10ms 10 Jul 2025 868th rahulbyte-js 342 556 10ms 25 Nov 2025 873rd amadeusdotpng 341 558 10ms 22 Apr 2023 873rd iliao2345 341 558 10ms 8 Jul 2025 875th lmolteno 340 559 10ms 3 Mar 2021 875th jmath3912 340 559 10ms 26 Apr 2024 877th estomagordo 🇳🇱 339 560 10ms 3 Aug 2019 877th gautambp 339 560 18ms 22 Jun 2025 877th iilegacyyii 339 560 17ms 30 Dec 2025 880th kalpanasuresh 339 561 10ms 26 Mar 2021 First Prev 801–880 of 1,169 Next Last