Binary Search implementation in Ruby
def binary_search(array, value, from=0, to=nil) to = array.count - 1 unless to mid = (from + to) / 2 if value < array[mid] return binary_search(array, value, from, mid - 1) elsif value > array[mid] return binary_search(array, value, mid + 1, to) else return mid end end puts binary_search([1,2,3,4,5,7,8,9,10,12,15,16,17,18], 15)