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) {        //binary search        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;            }            else if(A[mid]>target){                if(target>=A[left]){                    right=mid-1;                }                else{                    left++;                }            }            else{                if(target<=A[right]){                    left=mid+1;                }                else{                   right--;                 }            }        }        return -1;    }}