Search in Rotated Sorted Array

Suppose a sorted array is rotated at some pivot unknown to you beforehand.

(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).

You are given a target value to search. If found in the array return its index, otherwise return -1.

You may assume no duplicate exists in the array.

public class Solution {    public int search(int[] A, int target) {        if (A == null || A.length == 0) return -1;        int left = 0;        int right = A.length - 1;        while (left <= right) {            int mid = left + (right - left) / 2;            if (A[mid] == target) {                return mid;            }             if (A[left] <= A[mid]) {                if (A[left] <= target && target < A[mid]) {                    right = mid - 1;                } else {                    left = mid + 1;                }            } else {                if (A[mid] < target && target <= A[right]) {                    left = mid + 1;                } else {                    right = mid - 1;                }            }        }        return -1;    }}