$vars = 4;  # number of bits
for my $i (0 .. (1<<$vars)-1) {
    printf "%0${vars}b\n", $i;
}
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As for the header: you can cheat. All you have to do is sort the names in order of value, and print them out first. Above the table the code here creates.

And $vars in the above code must be the same as your number of variables. More beginners' fun.

my %to_combine = (
  A => "0,1",
  B => "0,1",
  C => "0,1",
  X => "0,1",
);

# Then the following prints it out...
print join " ", sort keys %to_combine;
print "\n";
my $s = join "\\ ", map "{$to_combine{$_}}", sort keys %to_combine;
print "$_\n" for glob $s;
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Terrific, Thanks a lot guys! You guys make problem look so simple which otherwise look invincible to me. Great!

Tilly, well your hash %to_combine is something that will be passed to the function as you have correctly shown. You have used a function "glob" which seems to work ideally for this job. Could you please elaborate how this function works. I tried checking about this function on google, but in most places it says "glob" is used for finding files/directories, such as *.pl etc. Please tell how it is doing the magic in the present context.

Hail Monks! Raj

I was looking back and realized that I never answered this.

The glob function produces a list of filename expansions in such a way as to mimic how /bin/csh does filename expansions on Unix. The manpage for csh in "Filename substitution" explains the metanotation that I took advantage of to make this give you something other than filenames.

Here is a little something allowing you to enter the number of ABC colums and to specify min and max values (ie 0 and 1, 0 and 9, a and z)

#!/usr/local/bin/perl -w
use strict;

print "enter number of columns:";
chomp (my $ow_many=<>);
my $min="f";
my $max="h";
my @array;

$array[$_-1]=$min for 1..$ow_many;

my $i=0;
while ($i <= $ow_many) {
    my $x="";
    for (@array) {$x=$_ if $_ gt $x}
    print join " ", @array, " $x\n";
    $i=0;
    my $carry=1;
    while ($carry) {
        if (defined $array[$i] && $array[$i] eq $max) {
            $array[$i]=$min;
        }else{
           $carry--;
           $array[$i]++;
        }
        $i++;
    }
}
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Cheers,
R.

You could use Algorithm::Loops for this, but that would probably get you a poor grade. You could search for that name and find some discussions about how it works (and probably some other ways of doing this type of thing). If it starts to make sense, then you could read the source code and see how it works.

"The number assigned to X is always more than the numbers assigned to variables in the first set."

I thought of solving it but couldn't arrive at a solution. The problem is that the number of variables in "First Set" may change from one case to the other, and my function should work for all such cases. I tried to use "for loops", but they wouldn't work because the number of "for loops" may change from cases to case, depending on the number of variables "First Set" has.

I am asking for suggestions rather than the code to solve this problem. This way I can write and test code myself and thereby learn more.

Cheers, Raj

for (<DATA>) {
    chomp; split(/ => /);
    $hash{$_[0]} = $_[1];
}
$data[$#data+1] = [split(/ /, $hash{$_})]
    for (sort keys %hash);

print join("\t", sort keys %hash) . "\n";
for (0..(1<<$#data+1)-1) {
    $bin = sprintf("%0".($#data+1)."b", $_);
    for (0..$#data) {
        print $data[$_][substr($bin,$_,1)]."\t"
    } print "\n";
}

__DATA__
A => 0 1
B => 2 3
C => 4 5
X => 6 7
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