[Leetcode] Insert Interval (Java)_leetcode insert interval java-优快云博客

本文链接：https://blog.youkuaiyun.com/StarCXDJ/article/details/18008367

本文介绍了一种在已排序的非重叠区间中插入新区间并进行必要合并的算法。通过两个实例演示了如何处理区间重叠的情况，并给出了完整的Java实现代码。

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Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).

You may assume that the intervals were initially sorted according to their start times.

Example 1:
Given intervals [1,3],[6,9], insert and merge [2,5] in as [1,5],[6,9].

Example 2:
Given [1,2],[3,5],[6,7],[8,10],[12,16], insert and merge [4,9] in as [1,2],[3,10],[12,16].

This is because the new interval [4,9] overlaps with [3,5],[6,7],[8,10].

插入，感觉考的是ListIterator的用法

/**
 * 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; }
 * }
 */
import java.util.ListIterator;
public class Solution {
    public ArrayList<Interval> insert(ArrayList<Interval> intervals, Interval newInterval) {
    	Interval temp = new Interval(newInterval.start, newInterval.end);
		ListIterator<Interval> iterator = intervals.listIterator();
		while(iterator.hasNext()){
			Interval interval = iterator.next();
			if(temp.end<interval.start){
				iterator.previous();
				iterator.add(temp);
				return intervals;
			}
			if(temp.start>interval.end)
				continue;
			temp=new Interval(Math.min(temp.start, interval.start), Math.max(temp.end, interval.end));
			iterator.remove();
		}
		intervals.add(temp);
		return intervals;       
    }
}