NOTE: The solution below is incorrect. Please refer to the latest
attempt instead.
Here's my shot at it:
use List::Util qw(reduce);
my (@teams, %emp);
my $n = <>;
for my $i (0 .. $n - 1)
{
my ($e1, $e2) = (split ' ', scalar <>);
push @{ $emp{$e1} }, $i;
push @{ $emp{$e2} }, $i;
$teams[$i] = 1;
}
my @picks;
sub pick {
my $pick = shift;
push @picks, $pick;
$teams[$_] = 0 for @{ $emp{$pick} };
delete $emp{$pick};
}
my @favorites = (1002, 2001);
$emp{$_} and pick($_) for @favorites;
while (1)
{
my $max =
reduce { $a->[1] > $b->[1] ? $a : $b }
map [ $_ => scalar(grep $teams[$_], @{ $emp{$_} }) ],
keys %emp;
my ($winner, $cnt) = @{ $max };
last if $cnt == 0;
pick($winner);
}
local $\ = "\n";
print scalar(@picks);
print for @picks;
Update: Now with favorites!