/* Returns either the index of the location in the array,
  or -1 if the array did not contain the targetValue */

var doSearch = function(array, targetValue) {
var guess;
var min = 0;
var max = array.length - 1;
var n = 0;

while(min <= max){
	guess = Math.floor((min + max) /2);
	n++;
	if(array[guess] === targetValue)
		println(array[guess]);
		println("Guesses:" +n);
		return guess;
	else if(array[guess] < targetValue)
		min = guess + 1;
	else
	 max = guess - 1;
}
	return -1;
}

var primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97];

var result = doSearch(primes, 73);

println("Found prime at index " + result);
Program.assertEqual(doSearch(primes, 73), 20);
Program.assertEqual(doSearch(primes, 2), 0);
Program.assertEqual(doSearch(primes, 3), 1);