Fastest Way To Find Mismatch Positions Between Two Strings of the Same Length

Question

I have a millions of pairs of string of same length which I want to compare and find the position where it has mismatches.

For example for each $str1 a

Answer 1

It sounds like this might be a performance critical part of your application. In this case, you may want to consider writing a C extension method to do the comparison.

Perl provides the XS extension mechanism which makes this reasonably straightforward.