[leetcode]Insert Interval

Insert Interval

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].

这道题是个好题。我的算法太渣了，直接贴人家的吧。

思路1 ： 二分查找插入区间，具体代码我没实现，大家直接戳这里->传送门

 

 

思路2 ： 传送门。

一般来说，只有这三种情况，交叉有着四种情况，其实大家还是看代码吧，代码比图还好看。。。

public class Solution {
    public List<Interval> insert(List<Interval> intervals, Interval newInterval) {
        List<Interval> res = new ArrayList<Interval>();
        for (Interval each : intervals) {
            if (each.end < newInterval.start)
                res.add(each);
            else if (each.start > newInterval.end) {
                res.add(newInterval);
                newInterval = each;
            } else {
                newInterval = new Interval(Math.min(each.start, newInterval.start), Math.max(each.end, newInterval.end));
            }
        }
        res.add(newInterval);
        return res;
    }
}