use strict; use warnings; my $string = "AAATTTAGTTCTTAAGGCTGACATCGGTTTACGTCAGCGTTACCCCCCAAGTTATTGGGGACTTT"; my @substrings; while($string =~ /([ACTG])(\1+)/g){ my $comb = $1.$2; my $len = length($1) + length($2); push @substrings, [$comb,$len]; } my @sorted = sort {$b->[1] <=> $a->[1]} @substrings; foreach my $substring (@sorted){ foreach my $element (@$substring){ print "$element "; } print "\n"; }