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 561st AlephSquirrel 825 93 9ms 30 Oct 2025 562nd Shanethegamer 🇺🇸 822 52 3ms 4 Nov 2025 563rd voytxt 🇨🇿 821 54 10ms 22 Nov 2025 563rd KatieLG 🇬🇧 821 54 10ms 30 Nov 2025 563rd KrausRaus 🇺🇸 821 54 10ms 3 Dec 2025 566th blaztoma 🇱🇹 820 96 132ms 30 Nov 2025 567th MeWhenI 🇻🇦 820 222 13ms 23 Nov 2025 568th KasperKivimaeki 🇫🇮 819 104 3ms 2 Nov 2025 569th MeWhenI 🇻🇦 818 59 257ms 23 Nov 2025 570th MeWhenI 🇻🇦 817 88 10ms 3 Dec 2025 571st MeWhenI 🇻🇦 816 55 35ms 21 Nov 2025 572nd dokutan 816 70 3ms 28 Nov 2025 573rd snoozingnewt 🇨🇦 816 94 8ms 30 Nov 2025 573rd blaztoma 🇱🇹 816 94 8ms 1 Dec 2025 573rd BREMAUCY 🇫🇷 816 94 8ms 6 Dec 2025 576th MeWhenI 🇻🇦 815 69 1,204ms 23 Nov 2025 577th AlephSquirrel 815 90 64ms 30 Nov 2025 578th CaedenHarper 🇨🇦 814 67 127ms 30 Nov 2025 579th Shanethegamer 🇺🇸 813 60 1ms 3 Nov 2025 580th DialFrost 🇸🇬 813 61 5ms 2 Dec 2025 581st albanian-laundromat 811 61 12ms 23 Nov 2025 581st hiichbindermax 811 61 12ms 3 Dec 2025 581st Emutis 🇱🇹 811 61 11ms 7 Dec 2025 581st karadigm01 811 61 12ms 20 days ago 585th snoozingnewt 🇨🇦 811 97 113ms 30 Nov 2025 586th CaedenHarper 🇨🇦 810 56 1,269ms 30 Nov 2025 587th luuumine 🇫🇷 810 58 5ms 3 Dec 2025 588th Shanethegamer 🇺🇸 810 73 4ms 3 Nov 2025 589th albanian-laundromat 810 103 299ms 23 Nov 2025 589th plcc0 810 103 281ms 22 days ago 591st CaedenHarper 🇨🇦 809 74 119ms 30 Nov 2025 592nd Shanethegamer 🇺🇸 809 83 12ms 2 Nov 2025 593rd albanian-laundromat 808 84 41ms 21 days ago 594th MeWhenI 🇻🇦 807 53 2ms 29 Nov 2025 595th emgordon154 807 54 138ms 21 Dec 2025 596th dokutan 807 61 152ms 28 Nov 2025 597th AlephSquirrel 807 67 2ms 24 days ago 598th snoozingnewt 🇨🇦 807 94 27ms 30 Nov 2025 599th CLOStrophobic 🇮🇹 807 95 8ms 3 Dec 2025 600th Maznek 806 55 10ms 10 Dec 2025 601st snoozingnewt 🇨🇦 806 60 935ms 1 Dec 2025 602nd MeWhenI 🇻🇦 806 79 7ms 24 Nov 2025 602nd Shanethegamer 🇺🇸 806 79 3ms 24 Nov 2025 602nd AlephSquirrel 806 79 4ms 30 Nov 2025 605th dokutan 805 92 480ms 28 Nov 2025 606th albanian-laundromat 803 78 41ms 24 Nov 2025 607th albanian-laundromat 801 77 2,407ms 23 Nov 2025 608th dokutan 800 78 444ms 24 Nov 2025 609th DialFrost 🇸🇬 799 66 84ms 3 Dec 2025 610th neosimsim 799 96 8ms 23 Nov 2025 611th JOrE20 798 62 12ms 25 Nov 2025 611th HumanoidCPU 798 62 12ms 29 Nov 2025 611th Yewzir 🇧🇪 798 62 12ms 30 Nov 2025 611th anter69 🇭🇺 798 62 12ms 30 Nov 2025 611th inventshah 798 62 11ms 8 Dec 2025 611th SB-945 798 62 13ms 19 Dec 2025 611th FlorianCassayre 🇫🇷 798 62 12ms 8 Feb 2026 611th xiaoyiming123 798 62 12ms 8 days ago 619th Shanethegamer 🇺🇸 797 92 65ms 3 Nov 2025 619th blaztoma 🇱🇹 797 92 64ms 2 Dec 2025 621st albanian-laundromat 796 60 421ms 23 Nov 2025 622nd Shanethegamer 🇺🇸 794 62 168ms 3 Nov 2025 623rd error256 794 79 89ms 23 days ago 624th dokutan 793 61 744ms 21 Feb 2026 625th bitsandbeyond 🇳🇱 793 72 3ms 2 Nov 2025 626th MeWhenI 🇻🇦 793 79 39ms 23 Nov 2025 627th Shanethegamer 🇺🇸 792 55 146ms 4 Nov 2025 628th emgordon154 791 78 2,564ms 21 Dec 2025 629th kmathis22 791 97 10ms 6 days ago 630th dokutan 789 75 4ms 2 Dec 2025 631st edsrzf 🇳🇿 789 93 64ms 1 Dec 2025 632nd Kacarott 🇦🇺 789 198 3ms 5 Dec 2025 633rd ovs-code 🇩🇪 788 77 6ms 29 Nov 2025 634th CaedenHarper 🇨🇦 787 57 34ms 29 Nov 2025 635th MeWhenI 🇻🇦 787 62 2ms 23 Nov 2025 636th MeWhenI 🇻🇦 787 63 5ms 24 Nov 2025 637th Shanethegamer 🇺🇸 787 100 123ms 3 Nov 2025 638th emgordon154 787 106 289ms 25 Nov 2025 639th tomh1012 782 97 28ms 12 Feb 2026 640th MeWhenI 🇻🇦 781 63 153ms 23 Nov 2025 First Prev 561–640 of 1,462 Next Last