Bubblesort in perl

This bubblesort sorts 3000 random integers between 1 and 1000 in 10 seconds.

#!perl



use strict;



my ($list_size, $max_num, @numbers, $start_time);



#Generate a large number of random integers

$list_size = 3000;

$max_num = 1000;

@numbers = ();

for(1..$list_size) {

  push(@numbers, int(rand($max_num)));

}



#Print out the number array, then sort it, then print it out again in sorted order

#print "\n\n@numbers";

$start_time = time;

bubblesort(\@numbers);

#print "\n\n@numbers";

print "BUBBLESORT sorted $list_size numbers between 1 and $max_num in " . (time - $start_time) . " seconds\n";



sub bubblesort {

  my( $numbers, $swaps );

  ($numbers) = @_;

  $swaps = 0;



  do {

    $swaps = 0;

    for(my $i=0; $i < $#{$numbers}; $i++) {

      if ( $numbers->[$i] > $numbers->[$i + 1] ) {

        swap( $i, $i+1, $numbers);

        $swaps++;

      }

    }

  } while( $swaps > 0 );

}





#A swap operation takes a list reference and exchanges the values at the indicated indices

#The swap operation allows quicksort to work in one list

sub swap {

  my( $index1, $index2, $anyarray ) = @_;

  $_ = $anyarray->[$index1];

  $anyarray->[$index1] = $anyarray->[$index2];

  $anyarray->[$index2] = $_;

}