https://www.nowcoder.com/practice/9f3231a991af4f55b95579b44b7a01ba?

class Solution {
public:
    int minNumberInRotateArray(vector<int> rotateArray) {
        if(rotateArray.empty())
        {
            return 0;
        }

        int right = rotateArray.size()-1;
        int left = 0, mid = 0;

        while(rotateArray[left] >= rotateArray[right])
        {
           mid = (left+right)>>1;
            if(right - left == 1){
            //两个下标已经相邻了
                mid = right;
                break;
            }

            if(rotateArray[mid]==rotateArray[left] &&
             rotateArray[mid]==rotateArray[right]) //特殊情况
            {
                int min = rotateArray[left];
                for(int i=left+1; i<right; i++)
                {
                    if(rotateArray[i] < min)
                    {
                        //更新最小
                        min=rotateArray[i];
                    }
                }
                
                //返回min
                return min;
            }
            else if(rotateArray[mid] >= rotateArray[left])//min在右面
            {
                left=mid;
            }
            else //最小值在左面
            {
                right=mid;
            }

        }
        
        return rotateArray[mid];
    }
};