RBSRecursion.java

package com.aniketh;
// RBS is Rotated Binary Search
public class RBSRecursion {
    public static void main(String[] args) {
        int[] arr = {5,6,7,8,9,1,2,3};
        System.out.println(search(arr, 8, 0, arr.length-1));
    }
    static int search(int[] arr, int target, int s, int e) {
        if (s > e) {
            return -1;
        }
        int m = s + (e - s) / 2;
        if (arr[m] == target) {
            return m;
        }
        // Conditions
        if (arr[s] <= arr[m]) {
            if (target >= arr[m] && target <= arr[m]) {
                return search(arr, target, s, m-1);
            } else {
                return search(arr, target, m+1, e);
            }
        }

        if (target >= arr[m] && target <= arr[e]) {
            return search(arr, target, m+1, e);
        } else {
            return search(arr, target, s, m-1);
        }
    }
}