RosettaCodeData/Task/Tree-traversal/Perl/tree-traversal.pl

37 lines
646 B
Perl

sub preorder
{
my $t = shift or return ();
return ($t->[0], preorder($t->[1]), preorder($t->[2]));
}
sub inorder
{
my $t = shift or return ();
return (inorder($t->[1]), $t->[0], inorder($t->[2]));
}
sub postorder
{
my $t = shift or return ();
return (postorder($t->[1]), postorder($t->[2]), $t->[0]);
}
sub depth
{
my @ret;
my @a = ($_[0]);
while (@a) {
my $v = shift @a or next;
push @ret, $v->[0];
push @a, @{$v}[1,2];
}
return @ret;
}
my $x = [1,[2,[4,[7]],[5]],[3,[6,[8],[9]]]];
print "pre: @{[preorder($x)]}\n";
print "in: @{[inorder($x)]}\n";
print "post: @{[postorder($x)]}\n";
print "depth: @{[depth($x)]}\n";