[Leetcode 33, Hard] Search in Rotated Sorted Array

Problem:

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.

Analysis:

Solutions:

C++:

int search(int A[], int n, int target) {
        if(n == 0)
            return -1;
            
        for(int start = 0, end = n -1; start <= end;) {
            if(A[start] == target)
                return start;
            else if(A[end] == target)
                return end;

            if(start == end || start == end - 1)
                break;

            int mid = (start + end) / 2;
            if(A[mid] == target)
                return mid;
            else if(A[mid] > A[start] && A[mid] > A[end]) {
                if(target > A[start] && target < A[mid])
                    end = mid;
                else
                    start = mid;
            } else {
                if(target > A[mid] && target < A[end])
                    start = mid;
                else
                    end = mid;
            }
        }

        return -1;
    }
           

Java :

Python: