binary search which returns index of found value.

BinarySearch.java

import java.util.Arrays;

class BinarySearch {

    public int search(int[] input, int searchInput) {
        int n = input.length;
        if (n == 0) {
            return -1;
        }
        int midPoint = n / 2;
        int midPointValue = input[midPoint];
        if (searchInput == midPointValue) {
            return midPoint;
        }
        if (searchInput < midPointValue) {
            int[] leftArray = Arrays.copyOfRange(input, 0, midPoint);
            return search(leftArray, searchInput);
        }
        if (searchInput > midPointValue) {
            int[] rightArray = Arrays.copyOfRange(input, midPoint + 1, n);
            int rightArrayIndex = search(rightArray, searchInput);
            return rightArrayIndex == -1 ? rightArrayIndex : midPoint + rightArrayIndex + 1;
        }
        return -1;
    }

}