#!/usr/bin/perl

use warnings;
use strict;

use vars qw($b $c $d $e $i $x);

sub insert {
    my $valuetoinsert = pop;
    my $position = pop;
    my @thelist = @_;
    splice(@thelist, $position, 0, $valuetoinsert);
    return @thelist;
}

my $nrlist = 500;
my $nrin = 200;
my @l = (1 .. $nrlist);
my @in = (1 ..$nrin);
$x = 0;
$b = $nrlist;
@l = insert(@l, int($b / 2), $in[$x]);
while ($x < $nrin) {
    $c = $b / 2;
    $d = int(($b - $c) / 2);
    $e = int(($b + $c) / 2);
    if ($d == 0 || $e == 0) {
        $b = $#l + 1;
        next;
    }
    @l = insert(@l, $d, $in[$x]);
    $x ++;
    @l = insert(@l, $e, $in[$x]);
    $x ++;
    $b = $c;
}

for($i = 0; $i <= $#l; $i++) {
    print "$i\t$l[$i]\n";
}