#!/usr/bin/env perl 
use strict;
use warnings;
use Benchmark 'cmpthese';

my @source;

for my $arrsize (1e6, 1e7, 1e8) {
    print "Source array has $arrsize elements\n";
    my @source;
    push @source, rand for 1..$arrsize;

    cmpthese (1e8, {
        'BUK' => ' my @b; $b[ $_-1 ] = $a[ $_-1 ] - $a[ $_ ] for 1 .. $#a; ',
        'ike1' => ' my @b; $b[ $_ ] = $a[ $_ ] - $a[ $_+1 ] for 0 .. $#a-1; ',
        'ike2' => ' my @b = @a; $b[ $_ ] -= $b[ $_+1 ] for 0 .. $#b-1; pop @b; '
    });
    print '-' x 80 . "\n";
}