NC48 #在旋转过的有序数组中寻找目标值#

先找到翻转的起始下标，通过判断nums[0]与target的相对大小来决定在哪一段上进行常规二分。

class Solution {
public:
    int binary_s(vector<int> nums, int target, int left, int right)
    {
        while(left <= right)
        {
            int middle = left + (right - left) / 2;
            if(nums[middle] == target) return middle;
            else if(nums[middle] < target) left = middle + 1;
            else if(nums[middle] > target) right = middle - 1;
        }
        return -1;
    }

    int search(vector<int>& nums, int target) {
        int move = 0, len = nums.size();
        for(int i = 0; i < len - 1; i++)
            if(nums[i] > nums[i + 1])
                move = i + 1;
        if(move == 0) return binary_s(nums, target, 0, len - 1);
        if(nums[0] > target) return binary_s(nums, target, move, len - 1);
        else return binary_s(nums, target, 0, move - 1);
    }
};