Binary search
Binary search is a searching algorithm to find the position of the searched value in a list by dividing the list into left and right sublists. Prior to performing this searching algorithm, we have to sort the list using the sorting algorithms we discussed in the Chapter 4, Arranging Data Elements Using a Sorting Algorithm.
Developing binary search algorithm
Suppose we have a sorted array containing these 15 elements {3, 8, 11, 15, 16, 23, 28, 30, 32, 39, 42, 44, 47, 48, 50}
and we need to find the position of 16
. The first thing the binary search does is to find the middle element, then compares it with the searched value. Since we've got 15 elements on the list, the middle index is 7
(since the array is a zero-based index), and the value of the index is 30
. Then, we compare 30
with our searched value, which is 16
. Since the middle value is greater than the value we are looking for, the searched value must be to the left of the middle index. So, we can take the left subarray...