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

my $number=1000;
my $string;
vec $string, $number, 1;

while ($number) {
    my $chance_step = 1/$number;
    my $rand=rand;
    my $i=0;
    while ($rand > 0) {
        if (vec $string, $i++, 1) {
            next
        } else {
            $rand-=$chance_step
        }
    }
    while (vec $string, $i, 1){$i++}
    vec($string, $i, 1)=1;
    print "$i, ";
    $number--
}