/**
knakul853
**/
class Solution {
public:
    vector<vector<int>> merge(vector<vector<int>>& intervals) {

        sort(intervals.begin(), intervals.end());

         int n = (int)intervals.size();

          vector<vector<int>>ans;

        int i=0, j=0;

        while(i < n )
        {
            j = i;
            int mx = intervals[i][1];
            while(j+1 < n && mx >=intervals[j+1][0])
            {
                mx = max(mx, intervals[j+1][1]);
                j++;
            }

            ans.push_back({intervals[i][0], mx});
            i=j+1;
        }

        return ans;

    }
};