#!/usr/bin/perl

# http://perlmonks.org/?node_id=1134550

use warnings;
use strict;

my (@left, %left, @top, %top, %values);
my $all = '';

while(<DATA>)
   {
   $all |= $_ for my ($left, $top, $value) = split;
   $left{$left}++ or push @left, $left;
   $top{$top}++ or push @top, $top;
   $values{$left}{$top} = $value;
   }

my $len = length $all;
my $fmt = join(' ', map "%${len}s", 0..@top) . "\n";

printf $fmt, '', @top;
for my $left (@left)
   {
   printf $fmt, $left, map $values{$left}{$_} // '', @top;
   }

__DATA__
aaa bbb 123
aaa ccc 234
aaa ddd 345
bbb ccc 456
bbb ddd 567
ccc ddd 678

##</code><code>##

    bbb ccc ddd
aaa 123 234 345
bbb     456 567
ccc         678