use strict;
use warnings;

my $str = <<STR;
AA SET1 0
AA SET2 1
AA SET3 0
BB SET1 0
BB SET3 0
CC SET1 2
CC SET2 3
STR

my %rows;
my %sets;

open my $fIn, '<', \$str or die "Can't open input file: $!\n";

while (defined (my $line = <$fIn>)) {
    chomp $line;

    my ($name, $set, $value) = split /\s+/, $line;

    next if !defined $value;

    $rows{$name}{$set} = $value;
    ++$sets{$set};
}

my @setNames = sort keys %sets;

print join ("\t", 'Name', @setNames), "\n";

for my $rowName (sort keys %rows) {
    print join ("\t",
        $rowName, map {defined $_ ? $_ : ''} @{$rows{$rowName}}{@setNames}),
        "\n";
}

##</code><code>##

Name	SET1	SET2	SET3
AA	0	1	0
BB	0		0
CC	2	3