leetcode 合并区间

使用最简单的排序方法；

/**
 * Definition for an interval.
 * public class Interval {
 *     int start;
 *     int end;
 *     Interval() { start = 0; end = 0; }
 *     Interval(int s, int e) { start = s; end = e; }
 * }
 */
public class Solution {
    public List<Interval> merge(List<Interval> intervals) {
        if(intervals.size()<=1) return intervals;
        ArrayList<Interval> arry=new ArrayList<Interval>();
        Comparator<Interval> cmp=new Comparator<Interval>(){
            public int compare(Interval v1,Interval v2)
            {
                return v1.start-v2.start;
            }
                
        
            
        };
            Collections.sort(intervals,cmp);
            Interval pre=intervals.get(0);
            for(int i=1;i<intervals.size();i++)
            {
                Interval cur=intervals.get(i);
                if(cur.start<=pre.end)
                {
                  pre=new Interval(pre.start,Math.max(cur.end,pre.end));//merge
                  
                }
                else
                {
                    arry.add(pre);
                    pre=cur;
                }
                
            }
            arry.add(pre);
            return arry;
           
    }
}