The following does what you want without recursion:

#!/usr/bin/perl -w

use strict;

use constant MIN => 0;
use constant MAX => 40000;

my($low, $high, $mid) = (MIN, MAX);

print "Think of a number between $low and $high\n";

while(1) {
  $mid = int(($low + $high) / 2);

  last if $low >= $high;

  print "How about $mid? Is it (l)ow, (h)igh or (c)orrect? : ";

  my $answer = lc(substr <STDIN>, 0, 1);

  $answer eq 'c' ? last             :
  $answer eq 'l' ? $low  = $mid + 1 :
  $answer eq 'h' ? $high = $mid - 1 :
  print "bad input\n";
}

print "The number you are thinking of is $mid!\n";

[download]

In reply to (dkubb) Re: (1) bushy recursion a good thing ? by dkubb
in thread bushy recursion a good thing ? by mandog

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.