#!/usr/bin/perl -w
use strict;

my @list = 1..10;

print binary_search(\@list, 3);

sub binary_search {
    my ($aref, $find) = @_;
    my  $mid;

    $mid = int $#$aref / 2;

    return 0 if $find == $aref->[$mid];
    return 1 if !$#$aref;

    if ($find > $aref->[$mid]) {
        @$aref = @$aref[++$mid..$#$aref];
        binary_search($aref, $find);
    }
    else {
        @$aref = @$aref[0..--$mid];
        binary_search($aref, $find);
    }
}

##</code><code>##

@$aref = @$aref[++$mid..$#$aref];

##</code><code>##

@$aref = @$aref[++$mid..-1];