题目

[033-Search-in-rotated-sorted-array]

算法

http://www.cnblogs.com/grandyang/p/4325648.html

http://blog.csdn.net/ljiabin/article/details/40453607

代码

class Solution {

public:

    int search(vector<int>& A,  int target) {

        int n=A.size();

        if (n == 0) return -1;

        int left = 0, right = n - 1;

        while (left <= right) {

            int mid = (left + right) / 2;

            if (A[mid] == target) return mid;

            else if (A[mid] < A[right]) {

                if (A[mid] < target && A[right] >= target) left = mid + 1;

                else right = mid - 1;

            } else {

                if (A[left] <= target && A[mid] > target) right = mid - 1;

                else left = mid + 1;

            }

        }

        return -1;

    }

};