4 ms·

I've done it ruby this way: text.scan(/(.)(.)(.)(.)(\3)(\2)(\1)/)

• Natsu 16y ago
  That's pretty frail. It won't catch palindromes with an even number of letters (e.g. ababbaba) and it'll only find those of at most 7 characters. Granted, you can use those matches to work outwards and search for more, but I didn't think the general solution was all that hard. Oddly enough, it didn't even occur to me to try a regex and I like using them quite a bit.