旋转数组的最小数字

    int minNumberInRotateArray(vector<int> rotateArray) {
        if(rotateArray.empty())return 0;
        int n = rotateArray.size();
        int lo = 0, hi = n - 1, mi = 0;
        while(lo <= hi){
            mi = ((hi - lo) >> 1) + lo;
            if(rotateArray[mi] >= rotateArray[0])lo = mi + 1;
            else
                hi = mi - 1;
        }
        return rotateArray[lo];
    }