Merge Intervals

1. Title

Merge Intervals

2. Http address

https://leetcode.com/problems/merge-intervals/

3. The question

Given a collection of intervals, merge all overlapping intervals.

For example,
Given [1,3],[2,6],[8,10],[15,18],
return [1,6],[8,10],[15,18].

4 My code(AC)

•  

   1 // Accepted
   2       public static List<Interval> merge(List<Interval> intervals) {
   3          
   4           List<Interval> res = new ArrayList<Interval>();
   5           if ( intervals == null || intervals.isEmpty() )
   6               return res;
   7           
   8           Comparator<Interval> com = new Comparator<Interval>(){
   9                   public int compare(Interval a ,Interval b)
  10                   {
  11                       if ( a.start < b.start) return -1;
  12                       else if ( a.start > b.start ) return 1;
  13                       else {
  14                           if ( a.end < b.end) return -1;
  15                           else if ( a.end > b.end ) return 1;
  16                           else return 0;
  17                       }
  18                   }
  19           };
  20           
  21           Collections.sort(intervals,com);
  22           
  23           for( int i = 0 ; i < intervals.size(); i++)
  24           {
  25               Interval cur = intervals.get(i);
  26               if ( res.isEmpty() )
  27               {
  28                   res.add(cur);
  29               }else{
  30                   Interval last = res.get(res.size() - 1);
  31                   if ( last.end >= cur.start)
  32                   {
  33                       last.end = Math.max(last.end, cur.end);
  34                   }else{
  35                       res.add(cur);
  36                   }
  37               }
  38           }
  39           return res;
  40         }
  41       

   

Merge Intervals

原文：http://www.cnblogs.com/ordili/p/4970052.html