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?
Tower of Hanoi in all languages 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 msbranicky 663 93 2,598ms 4 Dec 2025 802nd acotis 663 99 112ms 2 Jan 2026 803rd CaedenHarper 🇨🇦 662 157 1,890ms 30 Nov 2025 804th GolfingSuccess 🇬🇷 661 49 3ms 4 Nov 2025 805th bitsandbeyond 🇳🇱 661 119 121ms 31 Oct 2025 806th LostSyntax21 🇬🇧 660 75 18ms 30 Nov 2025 806th firegene 🇮🇪 660 75 11ms 20 Feb 2026 808th MeWhenI 🇻🇦 660 95 83ms 23 Nov 2025 809th Shanethegamer 🇺🇸 659 102 116ms 2 Nov 2025 810th bitsandbeyond 🇳🇱 656 75 148ms 5 Nov 2025 811th madex 🇩🇪 654 74 774ms 11 days ago 812th Yewzir 🇧🇪 654 116 28ms 30 Nov 2025 813th albanian-laundromat 653 91 4ms 24 Nov 2025 814th AutumnWind75 652 119 438ms 10 Dec 2025 815th Ripick 651 76 11ms 14 Nov 2025 815th scpchicken 🇵🇼 651 76 12ms 5 Dec 2025 817th GolfingSuccess 🇬🇷 651 157 1,502ms 7 Dec 2025 818th emgordon154 650 92 7ms 22 days ago 819th madex 🇩🇪 647 129 269ms 12 days ago 820th BREMAUCY 🇫🇷 646 74 474ms 1 Dec 2025 820th JOrE20 646 74 441ms 7 Jan 2026 822nd jameswmccarty 643 96 2,542ms 8 Feb 2026 823rd scpchicken 🇵🇼 643 100 10ms 13 days ago 824th mousetail 🇳🇱 642 77 12ms 23 Nov 2025 825th GolfingSuccess 🇬🇷 639 72 1ms 30 Oct 2025 826th AlephSquirrel 639 105 9ms 30 Nov 2025 827th dokutan 638 163 1,613ms 5 Dec 2025 828th HumanoidCPU 637 111 457ms 29 Nov 2025 829th msbranicky 637 131 303ms 4 Dec 2025 830th Herbert00709 🇵🇱 636 78 5ms 22 days ago 831st BREMAUCY 🇫🇷 636 97 2,505ms 3 Dec 2025 832nd HumanoidCPU 636 122 57ms 29 Nov 2025 833rd a6166231 🇨🇳 634 70 11ms 12 Feb 2026 834th Bmrl7 634 78 11ms 20 Dec 2025 835th D-MOVE 🇵🇭 632 71 42ms 21 days ago 836th prestosilver 🇺🇸 632 97 2ms 3 Dec 2025 837th scpchicken 🇵🇼 632 132 267ms 13 days ago 838th madex 🇩🇪 631 102 10ms 12 days ago 839th aksyristos 631 123 60ms 3 Dec 2025 839th yeminghan2021 631 123 63ms 3 Feb 2026 841st stackofbears 630 62 34ms 22 Dec 2025 842nd dokutan 630 95 7ms 25 Feb 2026 843rd scpchicken 🇵🇼 629 76 478ms 1 Jan 2026 844th jameswmccarty 628 77 716ms 8 Feb 2026 845th msbranicky 626 79 11ms 26 Nov 2025 845th nemoyatpeace 626 79 16ms 28 Dec 2025 845th nstearns96 🇬🇧 626 79 11ms 31 Dec 2025 845th tomh1012 626 79 10ms 24 days ago 845th Andrey2001 626 79 11ms 3 days ago 850th HumanoidCPU 626 105 119ms 29 Nov 2025 851st alexsave 625 71 10ms 30 Nov 2025 852nd Waffle3z 622 87 2ms 26 Dec 2025 852nd Andriamanitra 🇫🇮 622 87 2ms 24 days ago 854th msbranicky 622 108 8ms 4 Dec 2025 855th tomh1012 621 77 435ms 24 days ago 856th HumanoidCPU 621 85 91ms 29 Nov 2025 857th tomh1012 620 78 779ms 24 days ago 858th IISResetMe 619 78 343ms 30 Nov 2025 859th MeWhenI 🇻🇦 618 76 5ms 23 Nov 2025 860th HumanoidCPU 616 72 12ms 29 Nov 2025 860th olleicua 🇺🇸 616 72 10ms 8 Dec 2025 862nd JOrE20 614 102 43ms 28 Nov 2025 863rd MeWhenI 🇻🇦 613 104 1,025ms 23 Nov 2025 864th HumanoidCPU 612 121 478ms 30 Nov 2025 865th AlephSquirrel 611 79 304ms 30 Nov 2025 866th kmathis22 611 101 2,374ms 6 days ago 867th madeforlosers 608 73 10ms 9 days ago 868th MeWhenI 🇻🇦 607 100 6ms 24 Nov 2025 869th TheZwierzLF 🇵🇱 606 74 36ms 5 Jan 2026 870th tomh1012 606 103 427ms 12 Feb 2026 871st msbranicky 605 79 457ms 3 Dec 2025 871st madex 🇩🇪 605 79 447ms 12 days ago 871st Andrey2001 605 79 461ms 3 days ago 874th albanian-laundromat 605 82 5ms 25 Nov 2025 875th MeWhenI 🇻🇦 605 111 123ms 24 Nov 2025 876th HumanoidCPU 604 99 7ms 1 Dec 2025 877th Schmitt-Very-Cool 604 127 8ms 6 Dec 2025 878th dokutan 603 104 77ms 23 Jan 2026 879th HumanoidCPU 601 107 10ms 29 Nov 2025 880th CaedenHarper 🇨🇦 600 88 90ms 30 Nov 2025 First Prev 801–880 of 1,462 Next Last