学步园

常规做法，先排序然后合并。犯了一个错误，合并的时候默认为最后一个interval的end最大。。

import java.util.*;

public class Solution {
	
		
		class IntervalComp implements Comparator<Interval>{
			
			@Override
			public int compare(Interval inte1, Interval inte2)
			{
				if(inte1.start < inte2.start)
					return -1;
				else if(inte1.start == inte2.start)
					return 0;
				else
					return 1;
			}
		}
		
		void continueIntervals(List<Interval> intervals, int beg, int[] c, int[] maxEnd)
		{
			int k = beg;
			c[0] = 0;
			maxEnd[0] = intervals.get(beg).end;
			
			while(k < intervals.size() && maxEnd[0] >= intervals.get(k).start)
			{
				maxEnd[0] =  (maxEnd[0] > intervals.get(k).end) ? maxEnd[0] : intervals.get(k).end;
				
				c[0]++;
				k++;
			}
			
		}
		
		
	    public List<Interval> merge(List<Interval> intervals) {
	        
	    	List<Interval> mIntervals = new ArrayList<Interval>();
	    	
	    	if(intervals.size() == 0)
	    		return mIntervals;
	    	
	    	Collections.sort(intervals, new IntervalComp());
	    	
	    	int k = 0;
	    	int[] c = new int[1];
	    	int[] maxEnd = new int[1];
	    	
	    	while(k < intervals.size())
	    	{
	    		continueIntervals(intervals,k,c,maxEnd);
	    		
	    		if(c[0] == 1)
	    			mIntervals.add(intervals.get(k));
	    		else
	    		{
	    			Interval tinterval = new Interval(intervals.get(k).start, maxEnd[0]);
	    			mIntervals.add(tinterval);
	    		}
	    		
	    		k+=c[0];
	    	}

	    	
	    	return mIntervals;
	    }
	    
	    
	    
	    public static void main(String[] args){
	    	Solution sol = new Solution();
	    	List<Interval> intervals = new ArrayList<Interval>();
	    	
	    	intervals.add(new Interval(1,4));
	    	intervals.add(new Interval(2,3));
	    	
	    	
	    	List<Interval> mintervals = sol.merge(intervals);
	    	
	    	for(Interval interval : mintervals)
	    	{
	    		System.out.println(interval.start + " " + interval.end);
	    	}
	    	
	    }
}