#!/usr/bin/perl -w
 
use strict;
my($root, $n);
 
# first generate random inserts
while ($n++ < int(rand(5))+5) { insert($root, int(rand(1000)))}
 
# now dump out the tree all three ways
print "Pre order:  ";  pre_order($root);  print "\n";
print "In order:   ";  in_order($root);   print "\n";
print "Post order: ";  post_order($root); print "\n";
 
vertices($root);
exit;
 
###################
 
sub vertices { 
my $number=@_;
print "Number of vertices: $number";
}