Ctrl+P again to print, arrows/tab to navigate results, enter to confirm

    The Chess Move Validation hole will go live in approximately . Why not try and solve it ahead of time?

    Recent Solutions

    Hole Golfer Bytes Time Submitted
    Ordinal Numbers JOrE20 164
    Vampire Numbers JOrE20 422
    Smith Numbers JOrE20 🥉 224
    CSS Colors JOrE20 🥈 798
    Alphabetic Numbers JOrE20 🥈 721
    Transpose Sentence JOrE20 216
    Look and Say JOrE20 🥈 174
    Nim JOrE20 🥉 209
    Emojify JOrE20 🥈 305
    Arrows JOrE20 221
    Pangram Grep JOrE20 182
    Mahjong JOrE20 🥉 1,104
    Poker JOrE20 1,338
    Zodiac Signs JOrE20 320
    Ten-pin Bowling JOrE20 467
    Ascending Primes JOrE20 🥉 236
    United States JOrE20 276
    Minesweeper JOrE20 🥈 287
    Catalan’s Constant JOrE20 🥈 300
    Billiards JOrE20 🥈 257
    Happy Numbers JOrE20 131
    Gijswijt’s Sequence JOrE20 201
    Ulam Sequence JOrE20 🥉 168
    Lucky Tickets JOrE20 🥈 258
    Highly Composite Numbers JOrE20 443
    Card Number Validation JOrE20 220
    Set JOrE20 308
    Topological Sort JOrE20 🥈 251
    Taxicab Numbers JOrE20 🥈 134
    Fractions JOrE20 🥈 151
    Prime Numbers (Long) Florian-Mt 132
    Levenshtein Distance JOrE20 🥉 270
    Prime Numbers Florian-Mt 129
    Thue–Morse Constant HumanoidCPU 1,021
    Rijndael S-box MostParsingVex 🥉 142
    Kolakoski Constant JOrE20 🥉 246
    ASCII Table JOrE20 🥉 188
    Number Spiral JOrE20 🥉 171
    Thue–Morse Constant JOrE20 186
    Fibonacci JOrE20 69
    Divisors JOrE20 🥇 97
    Recamán albanian-laundromat 🥉 110
    Day of Week JOrE20 🥇 103
    Inventory Sequence JOrE20 🥉 103
    QR Decoder MostParsingVex 💎 285
    Hexagonal Spiral bitsandbeyond 397
    Seven Segment JOrE20 206
    99 Bottles of Beer JOrE20 370
    Rijndael S-box JOrE20 293
    Continued Fractions JOrE20 🥉 213
    Happy Numbers (Long) JOrE20 🥈 136
    Collatz JOrE20 🥉 121
    Arabic to Roman JOrE20 89
    Roman to Arabic JOrE20 🥇 76
    Tutorial quasar098 222
    Gray Code Decoder JOrE20 128
    Gray Code Encoder JOrE20 137
    Multitap Input JOrE20 🥉 251
    Kolakoski Sequence JOrE20 113
    ISBN JOrE20 174
    Tic-tac-toe JOrE20 🥈 183
    Emojify scpchicken 774
    DFA Simulator scpchicken 1,250
    Day of Week scpchicken 1,472
    CSS Colors scpchicken 7,095
    Continued Fractions scpchicken 1,107
    Connect Four scpchicken 🥈 938
    Yellowstone Permutation scpchicken 255
    Factorial Factorisation JOrE20 🥈 200
    Prime Numbers JOrE20 101
    Prime Numbers (Long) JOrE20 101
    PalindromemordnilaP JOrE20 179
    Intersection scpchicken 🥉 191
    Intersection JOrE20 💎 174
    Farey Sequence JOrE20 115
    Christmas Trees JOrE20 117
    Diamonds JOrE20 197
    N Queens JOrE20 292
    Arithmetic Numbers JOrE20 140
    brainfuck JOrE20 425
    Card Number Validation scpchicken 851
    Calendar scpchicken 🥉 1,036
    brainfuck scpchicken 1,470
    Billiards scpchicken 1,180
    Arrows scpchicken 1,265
    Foo Fizz Buzz Bar scpchicken 5,802
    Evil Numbers (Long) scpchicken 2,033
    Farey Sequence scpchicken 4,437
    Factorial Factorisation scpchicken 945
    Emirp Numbers (Long) scpchicken 1,239
    Emirp Numbers scpchicken 219
    Divisors scpchicken 1,249
    Diamonds scpchicken 1,186
    Collatz scpchicken 3,309
    Christmas Trees scpchicken 628
    Cubes scpchicken 4,184
    Alphabetic Numbers scpchicken 3,978
    Gijswijt’s Sequence scpchicken 2,083
    Catalan’s Constant scpchicken 1,086
    Catalan Numbers scpchicken 2,955