lintcode 容易题：Merge Intervals 合并区间

[                     [
[1, 3],               [1, 6],
[2, 6],      =>       [8, 10],
[8, 10],              [15, 18]
[15, 18]            ]
]

挑战

/**
* Definition of Interval:
* public class Interval {
*     int start, end;
*     Interval(int start, int end) {
*         this.start = start;
*         this.end = end;
*     }
*/

class Solution {
/**
* @param intervals: Sorted interval list.
* @return: A new sorted interval list.
*/
public List<Interval> merge(List<Interval> intervals) {
// write your code here
if(intervals == null || intervals.size()<=1){
return intervals;
}
Collections.sort(intervals,new IntervalComparator());
List<Interval> result = new ArrayList<Interval>();
Interval last = intervals.get(0);
for(int i=1;i<intervals.size();i++){
Interval curt = intervals.get(i);
if(curt.start<=last.end){
last.end = Math.max(last.end,curt.end);
}else{
result.add(last);
last = curt;
}
}
result.add(last);
return result;
}
private class IntervalComparator implements Comparator<Interval>{
public int compare(Interval a,Interval b){
return a.start - b.start;
}
}

}