#! /usr/bin/perl -w
use Data::Dumper;
use strict;

my $string ='    aaaa    bbbbccccccccbbbb   aaaabbbbbcdddddddddddddddddddd';
my $pos=0;
my @triples=();
my @reps=$string=~/((.)\2*)/g;
while (@reps) {               
  my $hits=shift @reps;                       
  my $char=shift @reps;
  push @triples, [$char, $pos, length $hits];
  $pos+=length $hits;
}
$Data::Dumper::Indent=0;                        
print Dumper @triples;
__DATA__
$VAR1 = [' ',0,4];$VAR2 = ['a','4',4];$VAR3 = [' ','8',4];$VAR4 = ['b','12',4];$VAR5 = ['c','16',8];$VAR6 = ['b','24',4];$VAR7 = [' ','28',3];$VAR8 = ['a','31',4];$VAR9 = ['b','35',5];$VAR10 = ['c','40',1];$VAR11 = ['d','41',20];