class Solution {
public:
    vector<vector<int>> merge(vector<vector<int>>& intervals) {
        vector<vector<int>> res;
        sort(intervals.begin(),intervals.end());
        res.push_back(intervals[0]);
        for(int i = 1;i<intervals.size();i++)
        {   
            if(intervals[i][0]<=res.back()[1])
            {
                res.back()[1] = max(res.back()[1],intervals[i][1]);
                //intervals[i] = res[res.size()-1];
            }
            else res.push_back(intervals[i]);
        }
        return res;
    }
};

class Solution {
public:
    int monotoneIncreasingDigits(int n) {
        string s = to_string(n);
        int location = s.size();
        for(int i = s.size()-1;i>=1;i--)
        {
            if(s[i-1]>s[i] || location == i && s[i-1] == s[i])location = i-1;
        }
        for(int i = location;i<s.size();i++)
        {
            if(i == location)s[location]--;
            else s[i] = '9';
        }
        return stoi(s);
    }
};