The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 3 days. Why not try and solve them ahead of time?
Collatz in Ruby 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 1st Steffan153 🇫🇮 1,000 46 39ms 3 hours ago 2nd Lydxn 🇨🇦 939 49 37ms 4 May 2022 2nd JayXon 🇺🇸 939 49 37ms 17 Oct 2022 2nd GrayJoKing 🇦🇺 939 49 37ms 15 Nov 2022 2nd radarek 🇵🇱 939 49 192ms 26 Aug 2025 6th canissimia 🇦🇶 920 50 42ms 5 May 2022 6th ovs-code 🇩🇪 920 50 223ms 7 May 2022 6th sisyphus-ppcg 🇦🇺 920 50 42ms 20 Feb 2023 6th sean-niemann 🇺🇸 920 50 44ms 9 Jun 2025 6th pardouin 🇫🇷 920 50 40ms 22 Aug 2025 11th nwellnhof 🇩🇪 902 51 40ms 4 May 2022 11th primo-ppcg 🇹🇭 902 51 42ms 6 May 2022 11th janlelis 902 51 38ms 10 May 2022 11th Natanaelel 🇸🇪 902 51 40ms 2 Jun 2022 11th blaztoma 🇱🇹 902 51 38ms 16 days ago 16th shinh 885 52 43ms 29 Jun 2022 16th MeWhenI 🇻🇦 885 52 67ms 25 Jul 2023 18th stefangimmillaro 868 53 39ms 2 Oct 2022 18th Haksell 🇦🇶 868 53 39ms 22 Feb 2023 20th Andriamanitra 🇫🇮 852 54 42ms 21 Jul 2022 20th jared-hughes 852 54 39ms 12 Sep 2022 20th OhmNomNom 852 54 41ms 7 Oct 2022 20th olleicua 🇺🇸 852 54 44ms 21 Jan 2024 20th LostSyntax21 🇬🇧 852 54 41ms 12 Mar 2025 20th AbrahamJLR 🇻🇪 852 54 40ms 4 Jun 2025 20th vishal-mohanty 852 54 39ms 25 Aug 2025 27th SirBogman 🇺🇸 836 55 42ms 5 May 2022 27th olivermrose 🇺🇸 836 55 40ms 6 May 2022 27th 4hg 🇺🇸 836 55 40ms 24 Aug 2022 27th DialFrost 🇸🇬 836 55 39ms 1 Jan 2023 27th error256 836 55 42ms 4 May 2024 32nd ChiefChippy2 821 56 45ms 4 May 2022 32nd aksyristos 821 56 38ms 29 Jan 2023 32nd anter69 🇭🇺 821 56 37ms 12 Feb 2024 32nd 3dm4n 🇫🇮 821 56 40ms 11 Mar 2024 32nd lgrandco 821 56 39ms 9 Oct 2024 32nd tatzyr 🇯🇵 821 56 41ms 10 Dec 2024 32nd D-MOVE 🇵🇭 821 56 41ms 8 Dec 2025 32nd denkyuu1 821 56 47ms 11 Feb 2026 40th Irratix 🇳🇱 807 57 40ms 29 Jun 2022 40th lacrosse 807 57 46ms 27 Nov 2025 42nd tkr-sh 🇰🇵 793 58 41ms 8 Sep 2022 42nd annaproxy 793 58 44ms 15 Sep 2023 42nd Shanethegamer 🇺🇸 793 58 39ms 25 Dec 2023 42nd emgordon154 793 58 41ms 26 Jul 2024 46th rniii 780 59 38ms 26 Mar 2024 46th dokutan 780 59 40ms 19 Oct 2024 46th ejini6969 780 59 39ms 13 Jun 2025 46th Laellekoenig 780 59 41ms 6 Nov 2025 50th DaCuteRaccoon 767 60 45ms 5 May 2022 50th razetime 767 60 43ms 22 Aug 2022 50th janbehrens 🇩🇪 767 60 39ms 17 May 2023 50th KatieLG 🇬🇧 767 60 44ms 2 Oct 2025 54th fynnkroeger 754 61 38ms 6 Jan 2023 54th aaronze 🇦🇺 754 61 38ms 17 Sep 2023 56th purp 742 62 38ms 13 Aug 2022 57th RuyiLi 730 63 43ms 21 Feb 2024 58th Waffle3z 719 64 39ms 6 May 2022 58th snoozingnewt 🇨🇦 719 64 39ms 25 Oct 2025 60th TheZwierzLF 🇵🇱 708 65 41ms 6 Jan 2026 61st Feniske 🇫🇷 697 66 40ms 8 Oct 2022 62nd adoxography 676 68 36ms 2 Mar 2024 63rd vrnprkh 657 70 39ms 30 Mar 2023 63rd truisseaux 657 70 37ms 12 Apr 2024 65th pfysches-boop 648 71 40ms 6 Aug 2023 65th madeforlosers 648 71 35ms 7 Nov 2024 67th beergit 639 72 36ms 7 Aug 2024 68th Ohh-n 630 73 38ms 9 Aug 2025 69th jamespeilunli 613 75 36ms 4 Jul 2022 70th kmathis22 590 78 38ms 5 Sep 2025 71st hollma 568 81 40ms 20 Oct 2023 72nd catflip 554 83 40ms 30 Nov 2023 73rd msbranicky 541 85 38ms 10 Oct 2023 74th Betuaredead 495 93 36ms 5 Jan 2023 75th yobatm 469 98 38ms 22 Aug 2025 76th sreedevk 🇺🇸 455 101 46ms 4 Dec 2022 77th HumanoidCPU 28 1,637 36ms 26 Dec 2024 78th JRaspass 🇬🇧 14 3,231 35ms 4 May 2022 78th KatieLG-Transpiler 🇬🇧 14 3,231 36ms 24 Jun 2022 78th retrohun 14 3,231 40ms 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