Fast Way to Find Difference between Two Strings of Equal Length in Perl

Question

Given pairs of string like this.

    my $s1 = \"ACTGGA\";
    my $s2 = \"AGTG-A\";

   # Note the string can be longer than this.

I would

Answer 1

Use binary bit ops on the complete strings.

Things like $s1 & $s2 or $s1 ^ $s2 run incredibly fast, and work with strings of arbitrary length.