5 ms·

I figured out Ranges! abac|accede|adead|babe|bead|bebed|bedad|bedded|bedead|bedeaf|caba|caffa|dace|dade|daff|dead|deed|deface|faded|faff|feed Edit: /s

• abus 13y ago
  Prime: ^x{2,3}$|^x{5}$|^x{7}$|^x{11}$|^x{13}$|^x{17}$|^x{19}$|^x{23}$|^x{29}$|^x{31}$|x{33}
  • jonahx 13y ago
    josephlord's solution is much nicer: ^(?!(..+)(\1)+$)
    • abus 13y ago
      Look at the parent.
• criswell 13y ago
  [a-f]{4,} works as well... but I do like your solution!
  • danielsamuels 13y ago
    [a-f]{4} is shorter.
    • josephlord 13y ago
      ^[a-f]*$ Is the same length too.