perl 二叉树示例程序

打印格式时费了点时间。

 

#!/usr/bin/perl


$rootname = "parent";
%tree = ("parentleft","child1",
                 "parentright","child2",
                 "child1left","grandchild1",
                 "child1right","grandchild2",
                 "child2left","grandchild3",
                 "child2right","grandchild4",
                 "grandchild3left","gc3child1",
                 "grandchild3right","gc3child2"
                );
$i=@lentree=values(%tree);
 
print ("\n节点数：".($i+1)."\n------------\n");                

&print_tree($rootname);

sub print_tree{
    local ($nodename)=@_;
    local ($leftchildname,$rightchildname);
  
    $leftchildname =$nodename."left";
    $rightchildname=$nodename."right";
    if ($tree{$leftchildname} ne ""){
     $j+=1;     
        &print_tree($tree{$leftchildname});
        $j-=1;
        }    

# print ("j=$j\n");

#    print ("k=$k\n");

print ((" |")x ($j+$k) );
print ( "$nodename\n");
    if ($tree{$rightchildname} ne ""){
        $k+=1;        
        &print_tree($tree{$rightchildname});
        $k-=1;
    }    

}