【二分查找】33. 搜索旋转排序数组

题目：

 

 

解答：

class Solution {
public:
    int search(vector<int>& nums, int target) 
    {
        int l = 0;
        int r = nums.size() -1;
        
        while (l <= r)
        {
            int mid = (l + r) >> 1;

            if (target == nums[mid]) 
            {
                return mid;
            }

            if (nums[l] <= nums[mid])
            {
                if (nums[l] <= target && target < nums[mid])
                    r = mid-1;
                else
                    l = mid+1;
            }
            else
            {
                if (nums[mid] < target && target <= nums[r])
                    l = mid +1;
                else
                    r = mid -1;
            }
        }
        return -1;
    }
};