Dear Monks,

I am trying to create a graphical structure with four nodes with names a, b, c and d. (%parentchild in the code below shows the graphical structure).
The program is giving the desired output for $nodes[0] (in the first foreach loop of the code below - output for $nodes[0] is also shown below). The output must contain all possible combinations of values of the node and its parents.
However, all subsequent iterations of this foreach loop (for $nodes[1], $nodes[2], $nodes[3], $nodes[4], and $nodes[5])
give incorrect results. I am not being able to figure out what mistake I am making.

Please guide me where the fault is.

Thanks very much.

#!/usr/bin/perl
use warnings;
use strict;


my $a=['a','p','q','r']; # a is the node name and p,q,r are the values
+ this node can assume. Likewise for other nodes.
my $b=['b','t','f'];
my $c=['c','nn','ny','yn','yy'];
my $d=['d','abv','avb','vab'];
my $values=[$b,$a,$c,$d]; 


my @nodes=('a','a','a','b','c','d');

foreach my $i (@nodes) {
    my $nodeparents=[parentchildrelationship($i)];
    print "$i $nodeparents $values\n";
    my $hash1=cpt($i,$nodeparents,$values);

    foreach my $i (keys %{$hash1}) {
        print "$i=>${$hash1}{$i}\n";
        #print "$i\n";
    }
}


sub cpt {
    my $node=$_[0];
    my @parents=@{$_[1]};
    my @nodevalues=@{$_[2]};
    my %hash=();
    my @nodeindex=();
    my @temparray=();
    my $string="";
    my @temp=();
    my $s;

    foreach my $i (@parents) {
        for (my $j=0;$j<=$#nodevalues;$j++) {
                if ($i eq ${$nodevalues[$j]}[0]) {
                    push (@nodeindex, $j); 
                }
        }
    }
    
    foreach my $i (reverse @nodeindex) { 
        push (@temparray, $nodevalues[$i]); 
    }

    for (my $i=0;$i<=$#temparray;$i++) {
        $string="$string"."${$temparray[$i]}[0] "; 
        shift @{$temparray[$i]};
        $temp[$i]=join (",",@{$temparray[$i]});
    }

    $hash{$string}=1; #fill %hash with the header
    $s = join "\\ ", map "{$_}", @temp;
    #print "$s\n";
    $hash{$_}=1 for glob $s; 
    
    return {%hash}; 
    
    $node="";
    @parents=(); 
    @nodevalues=();
    %hash=();
    @nodeindex=();
    @temparray=();
    $string="";
    @temp=();
    $s="";
}


sub parentchildrelationship {

    my $node=$_[0]; #or use "shift"
    my %parentchild=();
    my @nodeset=();

    %parentchild=('b'=>['none'], 'a'=>['b','d'], 'd'=>['b'], 'c'=>['b'
+]); #This is the structure of my graph, for example node 'b' has no p
+arent; node 'a' has parents in 'b','d'; and node d and c have both b 
+as parent.
    push (@nodeset, $node, @{$parentchild{$node}}); 
    return @nodeset;
}
[download]