use strict;
use warnings;

my $low = 1;
my $high = 10;
my @range=($low .. $high);
my $rand=$range[rand(@range)];     # <---
my $seed=$low-1;                   # <--- Works for all values of $low and $high.
my $count=1;
my $lastguess;
while ( $seed != $rand )
{
    #undef @range if ( $ count > 1);  # <--- Useless.
    @range=($low .. $high);
    $lastguess = $seed;
    $seed = $range[rand(@range)];     # <---
    if ( $seed < $rand )
    {
        print "You're too low - $seed (last guess = $lastguess)\n";
        $low=$seed+1;
        $count++;
    }
    elsif ( $seed > $rand )
    {
        print "you're too high - $seed (last guess = $lastguess)\n";
        $high=$seed-1;
        $count++;
    }
}

print "you got it in $count tries\n";
print "seed = $seed  rand = $rand ( last guess = $lastguess )\n";

##</code><code>##

use strict;
use warnings;

my $low   = 1;
my $high  = 10;
my $range = $high - $low + 1;
my $rand  = $low + int(rand($range));
my $count = 0;

for (;;) {
    my $guess = $low + int(rand($range));
    $count++;
    print("$count) Guessing $guess.");

    last if $guess == $rand;

    if ( $guess < $rand )
    {
        print " Too low.\n";
        $low = $guess + 1;
    }
    elsif ( $guess > $rand )
    {
        print " Too high.\n";
        $high = $guess - 1;
    }

    $range = $high - $low + 1;
}

if ($count == 1) {
   print " Got it on the first try!\n";
} else {
   print " Got it in $count tries.\n";
}