in reply to substrings that consist of repeating characters

In Perl length is cheap so calculate it when you need it. The following code is a little more Perlish but, other than using a threshold to drop out short strings, is similar to your code. For varieties sake the regex has changed slightly to be a little easier to grok:

use strict;
use warnings;

my $string = "AAATTTAGTTCTTAAGGCTGACATCGGTTTACGTCAGCGTTACCCCCCAAGTTATT
+GGGGACTTT";
my @runs;
my $threshold = 3;

length $1 >= $threshold && (push @runs, $1) while $string =~ /(A+|C+|G
++|T+)/g;
@runs = sort {length($b) <=> length($a)} @runs;
printf "@runs\n";

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Prints:

CCCCCC GGGG AAA TTT TTT TTT

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Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond

Replies are listed 'Best First'.
Re^2: substrings that consist of repeating characters
by LanX (Saint) on Sep 27, 2020 at 23:33 UTC
    > For varieties sake the regex has changed slightly to be a little easier to grok:

    Oh ... we got a one-liner :)

      DB<56> $_ = "AAATTTAGTTCTTAAGGCTGACATCGGTTTACGTCAGCGTTACCCCCCAAGTTAT
+TGGGGACTTT";

  DB<57> $threshold = 3;

  DB<58> x sort { length($b) <=> length($a) } grep { length >= $thresh
+old } /(A+|C+|G+|T+)/g
0  'CCCCCC'
1  'GGGG'
2  'AAA'
3  'TTT'
4  'TTT'
5  'TTT'
  DB<59>

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    EDIT

    and for the original problem 

      DB<59> x sort { length($b) <=> length($a) }  /(AA+|CC+|GG+|TT+)/g
0  'CCCCCC'
1  'GGGG'
2  'AAA'
3  'TTT'
4  'TTT'
5  'TTT'
6  'TT'
7  'TT'
8  'AA'
9  'GG'
10  'GG'
11  'TT'
12  'AA'
13  'TT'
14  'TT'
  DB<60>

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    Cheers Rolf
    (addicted to the Perl Programming Language :)
    Wikisyntax for the Monastery

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