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 {
    /**
     *@param A : an integer rotated sorted array
     *@param target :  an integer to be searched
     *return : an integer
     */
    public int search(int[] A, int target) {
        // write your code here
        int len = A.length;
        //error check
        if (A == null || len == 0) return -1;

        int lo = 0, hi = len - 1;
        while (lo <= hi) {
            int mid = (lo + hi) / 2;
            if (A[mid] == target) return mid;
            else if (A[mid] > A[hi]) {
            //left half is ordered
                if (A[lo] <= target && target < A[mid]) {
                    hi = mid - 1;
                } else {
                    lo = mid + 1;
                }
            } else { //right half is ordered
                if (A[mid] < target && target <= A[hi]) {
                    lo = mid + 1;
                } else {
                    hi = mid - 1;
                }
            }
        }
        return -1;
    }
}

class Solution(object):
    def search(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: int
        """

        if not nums or target is None:
            return -1

        lo, hi = 0, len(nums) - 1
        while lo <= hi:
            mid = (lo + hi) // 2
            if nums[mid] == target:
                return mid
            if nums[mid] > nums[hi]:
                if (nums[lo] <= target and target < nums[mid]):
                    hi = mid - 1
                else:
                    lo = mid + 1
            else:
                if (nums[mid] < target and target <= nums[hi]):
                    lo = mid + 1
                else:
                    hi = mid - 1
        return -1