#!/usr/bin/env perl
use strict;
use warnings;
use Algorithm::Loops qw(NestedLoops);
use Text::Levenshtein::XS qw(distance);
my @chars = qw(A M N U);
my $depth = 5; # We're taking "five at a time" from A, M, N, U.
my $min_dist = 3; # We need a minimum difference of 3 characters.
my @strings;
NestedLoops(
[ ([@chars]) x $depth ],
sub { push @strings, join('', @_) },
);
my $count = 0;
foreach my $left (@strings) {
foreach my $right (@strings) {
if (distance($left, $right) >= $min_dist) {
print ++$count, ": $left <=> $right\n";
}
}
}
print "\n$count pairs with minimum difference of $min_dist from a set
+of ",
scalar(@chars), " characters taken $depth at a time.\n";
Algorithm::Loops and Text::Levenshtein make it easy to generate the list of hits.
Output:
1: AAAAA <=> AAMMM
2: AAAAA <=> AAMMN
3: AAAAA <=> AAMMU
4: AAAAA <=> AAMNM
5: AAAAA <=> AAMNN
.... # many lines deleted
917168: UUUUU <=> UUNMM
917169: UUUUU <=> UUNMN
917170: UUUUU <=> UUNNA
917171: UUUUU <=> UUNNM
917172: UUUUU <=> UUNNN
917172 pairs with minimum difference of 3 from a set of 4 characters t
+aken 5 at a time.
