#!/usr/bin/perl -w

use strict;

##

my %letters=(
             A => 5,
             B => 1,
             C => 2,
             D => 5,
             E => 4,
            );

my $reps=3;
my %reps;

## hackarific!
my $pos=1;
my $dir=1;

## keep going until we run out
while (keys %letters) {
  ## get highest
  my($h,undef)=sort { $letters{$b} <=> $letters{$a} } keys %letters;

  ## note the grouping
  $reps{$pos}{letter}.=$h;
  $reps{$pos}{size}+=$letters{$h};

  delete $letters{$h};

  ## sorry folks, couldn't think of a better way fast enough :)
  if ($dir==1) {
    $pos++;
    if ($pos>$reps) {
      $pos--;
      $dir=0;
    }
  }
  else {
    $pos--;
    if ($pos==0) {
      $pos++;
      $dir=1;
    }
  }
}

for my $r (keys %reps) {
  print "$r: $reps{$r}{letter} $reps{$r}{size}\n";
}