Leetcode解题-Insert Interval

描述

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].

分析

看似简单，写对了不容易。思路是这样的，遍历已有区间，和新区间进行比较，有三种情况

1. 没有重叠，当前区间整体在新区间前面，则当前区间添加到结果集。
2. 没有重叠，当前区间整体在新区间后面，添加新区间到结果集。后面的区间可以一一添加即可。
3. 有重叠，把当前区间和新区间合并，生成的新区间继续和后面的区间进行上述过程。

代码

Python

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class (object): def insert(self, intervals, newInterval): """ :type intervals: List[Interval] :type newInterval: Interval :rtype: List[Interval] """ rs = [] for v in intervals: if v.end < newInterval.start: rs.append(v) elif v.start > newInterval.end: rs.append(newInterval) newInterval = v else: newInterval.start = min(v.start, newInterval.start) newInterval.end = max(v.end, newInterval.end) rs.append(newInterval) return rs