#!/bin/bash/perl

@tests = ("ABCGE ABCGE", "ABCGE FGCGB", "ABCGE JHAGT");

my @tests = (
    [qw{ABCGE ABCGE}],
    [qw{ABCGE FGCGB}],
    [qw{ABCGE JHAGT}],
);

foreach $strings (@tests) {
    my $diff = 0;

    for my $i (0 .. length($strings->[0]) - 1) {
        my @chars = map substr($strings->[$_], $i, 1), 0, 1;
        ++$diff if $chars[0] ne $chars[1];
    }

    print "@$strings $diff\n";
}