#!/usr/bin/perl

@num_list1=(34,2,65,345,987,23,12,45,62,100);

@num_list= sort {a <=> b} @num_list1;
$low=0;
$found_key=0;
$index;
$high=$#num_list;
print "enter the key: \t";
chomp($key=<STDIN>);

while($high>=$low && !$found_key)
{
	$mid=($low+$high)/2;
	if ($key == @num_list[$mid])
		{
			$found_key=1;
			$index = int($mid);
		}

	if ($key > @num_list[$mid])
		{
			$low = $mid+1;
		}
	if ($key < @num_list[$mid])
		{
			$high = $mid-1;
		}
}

if ($found_key) {
	print " The key is $index\n";
}
else {print "key is not found";}