Re: Very Large Hex Combinations

[ikegami]

People have suggested ways of working with numbers. I think it's faster to work with strings in this case (because it reduces greatly the number of calls to sprintf):

my @bytes = map { sprintf('%02X', $_) } 0..255;

foreach my $i (@bytes) {
foreach my $j (@bytes) {
foreach my $k (@bytes) {
foreach my $l (@bytes) {
foreach my $m (@bytes) {
foreach my $n (@bytes) {
   print("$i$j$k$l$m$n\n");
}}}}}}

Or you could use NestedLoops in Algorithm::Loops:

use Algorithm::Loops qw( NestedLoops );

my @bytes = map { sprintf('%02X', $_) } 0..255;

my $num_bytes = 6;

NestedLoops(
   [ ( [ @bytes ] ) x $bytes ],
   sub {
      print(join('', @_), "\n");
   }
);

[danambroseUK]

Thanks all for the *very* quick replies....


Ikegami's idea with using strings seems to be quicker - my next question is how would I expand the bellow code to produce larger hex patterns?



my @bytes = map { sprintf('%02X', $_) } 0..255;

foreach my $i (@bytes) {
foreach my $j (@bytes) {
foreach my $k (@bytes) {
foreach my $l (@bytes) {
foreach my $m (@bytes) {
foreach my $n (@bytes) {
   print("$i$j$k$l$m$n\n");
}}}}}}



Many thanks
Dan

[ikegami]

How large? That produces all patterns from 000000000000 to FFFFFFFFFFFF. Add more loops to make it bigger, or increase $num_bytes in my second snippet.

[Taulmarill]

i think one should use recursion here, something like this maybe


use strict;
use warnings;

my @charset = ( 0..9, "A".."F" );
rec( 8 );

sub rec {
    my $deep = shift;
    my $string = shift || '';
    if ( $deep-- ) {
        for my $char ( @charset ) {
            rec( $deep, $string . $char );
        }
    }
    else {
        print "$string\n";
    }
}

[danambroseUK]

Its a crazy idea but what I am trying to do is create every combination possible of a 640x480 bitmap file.

Yes this would take forever to do - but just imagine if every photo was created - we would have every photo of everything. Every photo ever taken and every photo to be taken- Effectivly a time machine!!

Jokes aside, how would this be achieved?


Thanks,
Dan