Whatever you do, don't generate a random number and then try to verify whether you've used it before. That's a recipe for disaster. It will seem ok at first, but once your halfway through your range, you are going to (statistically) have to generate 450,000 random numbers before you find one that you haven't used before! (I just KNOW a mathematician is gonna correct that last bit:)

If you have an urn with 50 blue marbles (representing already seen), and 50 red marbles (not yet seen), do you really think that the average number of draws (with replacement) that you need to make in order to choose a red marble is anywhere near 50? (remember, at this point the probability of drawing a red marble on a given draw is still a relatively high 0.5)
:-)

In reply to Re: Re: Generating random 6 digit numbers by Anonymous Monk
in thread Generating random 6 digit numbers by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.