[LeetCode] 56. Merge Intervals（vector sort）

 /**
  * 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;
     }
 };