in reply to Re: Detecting transpositions
in thread Detecting transpositions

Or even shorter... Albeit about 3 times slower on long strings and 30% faster for short... 
sub comp {
    local $_ = $_[0] ^ $_[1];
    return s/([^\x00])\1//g==1 && !tr/\x00/1/c;
}

[download]


T I M T O W T D I

Replies are listed 'Best First'.
Re: Detecting transpositions
by Abigail-II (Bishop) on Aug 06, 2003 at 15:52 UTC
    That doesn't return the index of where the transposition happens, does it?

    Abigail

[reply]
      So here it is with bonus, just a little longer... And now, its just a little faster than yours. Except on large identical strings where it is 3 times faster because of the first line. Without it the regexp would perform very slow. 
      sub comp {
    return -1 if $_[0] eq $_[1];
    local $_ = $_[0] ^ $_[1];
    /^([\x00]*)([^\x00])\2[\x00]*$/;
    $1 ? length$1 : -1;
}

      [download]


      T I M T O W T D I
[reply]
[d/l]
      No, that was only a bonus ;)

      T I M T O W T D I
[reply]
[d/l]

In Section Seekers of Perl Wisdom