[khanacademy] Ciencias de la computación Algoritmos

gistfile1.txt

// Desafío: búsqueda binaria

/* 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 min = 0;
	var max = array.length - 1;
    var guess;
    var guessTotal = 0;
    while(min <= max) {
        guess = Math.floor((max + min) / 2); 
        println(guess);
        guessTotal++;
        if(array[guess] === targetValue){ 
            println(guessTotal);
            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, 7);
println("Found prime at index " + result);


Program.assertEqual(doSearch(primes, 73), 20);
Program.assertEqual(doSearch(primes, 5), 2);
Program.assertEqual(doSearch(primes, 7), 3);