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.

Have you met this question in a real interview? Yes
Example
For [4, 5, 1, 2, 3] and target=1, return 2.

For [4, 5, 1, 2, 3] and target=0, return -1.

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