Binary Search in recursive way

BinarySearchRecursive.java

public class BinarySearchRecursive {
	public static int search(int[] arr, int start, int end, int num) {
		if (end - start == 1) {
			if (arr[start] == num) {
				return start;
			} else if (arr[end] == num) {
				return end;
			} else {
				return -1;
			}
		} else {
			int mid = (start + end) / 2;
			
			if (arr[mid] == num) {
				return num;
			} else {
				if (arr[mid] < num) {
					return search(arr, mid, end, num);
				} else {
					return search(arr, start, mid - 1, num);
				}
			}
		}
	}
}