AndrewPFindIndex.pm

package AndrewPFindIndex;

use strict;
use warnings;
use Data::Dumper;



# sorted array
my $arr = [1,2,3,5,95,97,100];

sub new{
	my $c = shift;
	my $class = ref $c || $c;
	my %arg = @_;
	
	my $o = {};
	bless $o, $class;
	
	return $o;
}


sub find{
        my $o = shift;
       
        my ($word) = @_;
	my $low = 0;
	my $high = @$arr - 1;
	my $step = 0;
	
	while ( $low <= $high ){
		my $try = int( ($low+$high) / 2 );
		$step ++;
		
		$low  = $try+1, next if $arr->[$try] < $word;
		$high = $try-1, next if $arr->[$try] > $word;
		
		return [$try, $step];
	}
	
	[undef, $step];
}


1;