The simplest way to do it, demonstrated in the debugger

  DB<39> $_ = "AAATTTAGTTCTTAAGGCTGACATCGGTTTACGTCAGCGTTACCCCCCAAGTTAT
+TGGGGACTTT";

  DB<40> push @substr, $1 while /((\w)\2+)/g

  DB<41> @sorted = sort { length($b) <=> length($a) } @substr

  DB<42> x @sorted
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<43>

[download]

Storing the length in @substr for a Schwartzian transform might be faster, but I wouldn't bet on this.

IMHO is length only doing a simple lookup of the pre-calculated length inside Perl's data-structure for strings and should be pretty fast.

HTH! :)

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

update
you could also do sort and dump in one line:

  DB<43> print join "\n", sort { length($b)<=>length($a) } @substr
CCCCCC
GGGG
AAA
TTT
TTT
TTT
TT
TT
AA
GG
GG
TT
AA
TT
TT
  DB<44>

[download]

In reply to Re: substrings that consist of repeating characters by LanX
in thread substrings that consist of repeating characters by Anonymous Monk

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