Write a recursive method named binarySearch that accepts a sorted array of integers and an integer target value and uses a recursive binary search algorithm to find and return an index at which that target value is found in the array.
If the target value is not found in the array, return -1.
The following code shows some example calls and their expected return values:
// index 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
int[] a = {-4, 2, 7, 10, 15, 20, 22, 25, 30, 36, 42, 50, 56, 68, 85, 92, 103};
int index = binarySearch(a, 42); // 10
int index = binarySearch(a, 66); // -1
You should assume that the array's elements are already sorted; you do not need to handle the case of an unsorted array.
Your method must be recursive and must use a binary search algorithm.
Do not use loops or auxiliary data structures.
