Leetcode: 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.

int search(int A[], int n, int target) {
        // Note: The Solution object is instantiated only once.
        int begin = 0;
		int end = n-1;
		while(begin < end)
		{
			int mid = (begin+end)/2;
			if(A[mid] == target)return mid;
			else if(A[begin] <= A[mid])
			{
				if(A[begin] <= target && target < A[mid])
					end = mid-1;
				else
					begin = mid+1;
			}
			else
			{
				if(A[mid] < target && target <= A[end])
					begin = mid+1;
				else
					end = mid-1;
			}
		}
		if(begin==end && A[begin]==target)
			return begin;
		else
			return -1;
    }