To prove safety offer- searching and sorting - the minimum number of rotating array

Title Description

The beginning of an array of several elements moved to the end of the array, the array we call rotation. A non-descending order of the input array of a rotation of the output rotary smallest element array. For example, an array {3,4,5,1,2} {1,2,3,4,5} is a rotation of the array to a minimum. NOTE: All the elements are given in greater than 0, if the array size is 0, return 0.

analysis

Binary search.

Code

class Solution {
public:
    int minNumberInRotateArray(vector<int> rotateArray) {
        if(rotateArray.empty())
            return 0;
        int low = 0;
        int high = rotateArray.size() - 1;
        int mid = 0;
        
        while(low < high) {
            if(rotateArray[low] < rotateArray[high])
                return rotateArray[low];
            mid = low + (high - low) / 2;
            if(rotateArray[low] < rotateArray[mid])
                low = mid + 1;
            else if(rotateArray[mid] < rotateArray[high])
                high = mid;
            else
                low++;
        }
        return rotateArray[low];
    }
};