Leetcode-Merge Intervals

 1 /**
 2  * Definition for an interval.
 3  * public class Interval {
 4  *     int start;
 5  *     int end;
 6  *     Interval() { start = 0; end = 0; }
 7  *     Interval(int s, int e) { start = s; end = e; }
 8  * }
 9  */
10 public class Solution {
11     public List<Interval> merge(List<Interval> intervals) {
12         if (intervals.size()==0)
13             return intervals;
14         
15         int index=0;
16         List<Integer> start = new ArrayList<Integer>();
17         List<Integer> end = new ArrayList<Integer>();
18         for (int i=0;i<intervals.size();i++){
19             start.add(intervals.get(i).start);
20             end.add(intervals.get(i).end);
21         }
22         Collections.sort(start);
23         Collections.sort(end);
24         
25         List<Interval> newList = new ArrayList<Interval>();
26         Interval newIn = null;
27         int st,et;
28         while (index<intervals.size()){
29             st = start.get(index);
30             newIn = new Interval(st,-1);
31             if (index+1==intervals.size()){
32                 newIn.end = end.get(index);
33                 newList.add(newIn);
34                 break;
35             }
36             while (start.get(index+1)<=end.get(index)){
37                 index++;
38                 if (index+1==intervals.size()){
39                     break;
40                 }
41             }
42             newIn.end = end.get(index);
43             newList.add(newIn);
44             index++;
45         }
46         
47         return newList;
48     }
49 }