The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Pernicious Numbers in C in bytes. 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 Bytes Time Submitted 81st cmayer777 632 76 2ms 14 Oct 2022 81st c0d3-4-F00d 🇩🇪 632 76 1ms 6 Jun 2023 81st LorenzoDeGaspari 632 76 1ms 3 May 2024 84th jtaxen 623 77 1ms 7 Apr 2024 84th Jonatan6 🇩🇰 623 77 1ms 27 Apr 2024 86th neihousaigaai 615 78 1ms 27 Mar 2021 86th Heathcorp 🇦🇺 615 78 1ms 10 Apr 2022 86th test-user1337 615 78 1ms 29 Aug 2023 86th Lv0Sys 🇵🇱 615 78 1ms 1 Jun 2025 90th heypwesto 🇳🇿 608 79 1ms 21 Apr 2021 90th Spruill-1 608 79 1ms 12 Sep 2021 92nd ibexq 600 80 2ms 30 Sep 2022 93rd TeodorDyakov 🇧🇬 593 81 2ms 26 Feb 2025 94th Re-Adventures 🇮🇳 585 82 1ms 8 Nov 2021 94th mttcrn 585 82 2ms 21 Mar 2025 96th DrPiranoid 578 83 1ms 7 Oct 2022 96th trist224 🇫🇷 578 83 1ms 14 Dec 2022 96th CatsAreFluffy 578 83 1ms 6 Mar 2023 96th nyoshe 578 83 1ms 19 Sep 2023 100th alexjlaberge 571 84 1ms 19 Sep 2019 101st Luca2812 565 85 1ms 5 Mar 2024 102nd HumanoidCPU 558 86 1ms 12 May 2024 103rd prestosilver 🇺🇸 539 89 2ms 17 hours ago 104th Alesun 🇮🇹 527 91 1ms 14 Oct 2019 105th aksyristos 516 93 1ms 28 Oct 2022 106th msbranicky 505 95 1ms 28 Aug 2023 107th Maashau 495 97 2ms 1 Dec 2025 108th warmCabin 485 99 1ms 13 Nov 2023 109th AkashTandon167 480 100 1ms 12 Nov 2019 110th RealAMC 🇳🇿 466 103 1ms 15 Nov 2023 111th AIn0n 457 105 1ms 15 Jul 2021 112th jngbsn 444 108 1ms 2 Mar 2019 113th ramytarchichy 432 111 1ms 23 Jun 2019 114th hjcafaroUC 414 116 1ms 7 Aug 2020 114th tegenton 414 116 1ms 14 Oct 2021 114th Haksell 🇦🇶 414 116 2ms 28 Feb 2023 114th Mabeloid 🇳🇴 414 116 1ms 3 Oct 2024 118th SirObby 🇫🇮 407 118 2ms 18 Oct 2025 119th generot 🇧🇬 400 120 1ms 3 Jul 2020 120th aDwarfNamedUrist 384 125 1ms 11 Jan 2024 121st osmith93 378 127 1ms 12 Dec 2020 122nd aubergine-sauce 364 132 1ms 26 May 2023 122nd masflam 364 132 2ms 21 Jun 2024 124th Giantnoodlemonster 333 144 1ms 10 Nov 2024 125th AlexOgn 327 147 1ms 3 Jul 2020 125th dillon-duncando 327 147 1ms 24 Dec 2021 127th kasarino 320 150 2ms 2 days ago 128th KatieLG 🇬🇧 316 152 2ms 1 Dec 2020 128th mokymok 🇺🇸 316 152 1ms 11 Nov 2021 128th 0xV0RT3X 316 152 1ms 5 Mar 2024 131st KatieLG-Transpiler 🇬🇧 312 154 1ms 23 Jun 2022 132nd zt14427 281 171 2ms 12 Aug 2023 133rd ElevatorShaft 250 192 2ms 15 Jan 2020 134th kevinnaviapaiva 155 310 2ms 24 Feb 2025 135th milliorn 129 371 1ms 17 Mar 2020 136th tanguysegarra 59 818 1ms 8 Jun 2019 First Prev 81–136 of 136