in reply to Retrieving data with largest count

Please post your code the next time, often a few small changes suffice to make such a program work.

...
my %best;
while (my $line=<YOURFILE>) {
  chomp $line;
  my ($item,$group,count)= split(/\s+/,$line);
  if ((not exists $best{$group}) or $best{$group}{count}<$count) {
    $best{$group}{count}=$count;
    $best{$group}{item}= $item;
  }
}


#to print them out
foreach my $group ( keys %best) {
  print "$best{$group}{item} $group $best{$group}{count}\n";
}

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PS: You didn't specify what should happen when two items in a group have the same count.

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Re^2: Retrieving data with largest count
by Angharad (Pilgrim) on Jun 02, 2009 at 15:15 UTC
    Many thanks for the advice so far. Much appreciated. In answer to your question, if two items have the same count, choosing an item at random is fine.
[reply]
      "choosing an item at random is fine"

      and also the hardest option. All candidates in a group have to be retained until processing the input data is complete, then all groups have to be checked for multiple candidate items and a random item selected.

      If either 'first' or 'last' is also fine then either of those is easier to implement.

      True laziness is hard work
[reply]

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