Search in Rotated Sorted Array

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.

------------------------------- codes -----------------------------------
class Solution {
public:
    int search(int A[], int n, int target) {
        if (n == 0) {
            return -1;
        }
        if (target == A[0]) {
            return 0;
        }
        int start = 0;
        int end = n-1;
        while (start + 1 < end) {
            int mid = start + (end - start) / 2;
            if (target > A[0]) {
                if (A[mid] < A[0] || A[mid] > target) {
                    end = mid;
                } else {
                    start = mid;
                }
            } else {
                if (A[mid] >= A[0] || A[mid] < target) {
                    start = mid;
                } else {
                    end = mid;
                }
            }
        }
        if (A[start] == target) {
            return start;
        }
        if (A[end] == target) {
            return end;
        }
        return -1;
    }
};