/**

  * Definition for an interval.

  * struct Interval {

  *     int start;

  *     int end;

  *     Interval() : start(0), end(0) {}

  *     Interval(int s, int e) : start(s), end(e) {}

  * };

  */

 class Solution

 {

 public:

     static bool cmp(Interval &a,Interval &b)

     {

         return a.start < b.start;

     }

     vector<Interval> merge(vector<Interval>& intervals)

     {

         if(intervals.empty()) return vector<Interval> {};

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

         vector<Interval> res;

         res.push_back(intervals[]);

         for(int i = ; i < intervals.size(); i ++)

         {

             if(intervals[i].start > res.back().end)

                 res.push_back(intervals[i]);

             else

                 res.back().end = max(res.back().end, intervals[i].end);

         }

         return res;

     }

 };