Leetcode Meeting room問題系列 - 1

這個問題系列就是list裡面每個元素都有一個start和end時間.

google和amazon經常考的題目。

1.Merge Intervals(medium)

https://leetcode.com/problems/merge-intervals/

2. Meeting Rooms (easy)

https://leetcode.com/problems/meeting-rooms/

3. Meeting Rooms II(Medium)

https://leetcode.com/problems/meeting-rooms-ii/

4. Partition Labels(Medlium)

https://leetcode.com/problems/partition-labels/

5. Employee Free Time (hard)

https://leetcode.com/problems/employee-free-time/

 

這類問題主要是數值範圍交叉問題，比如問題 2，問題3， 問題1

問題2就是給你一個會議時間集合list，每個元素有開始和結束時間。看看是否一個人可以參加所有的會議。

比如下面的例子

Input:[[0,30],[5,10],[15,20]]

Output:false

Example 2:

Input:[[7,10],[2,4]]

Output:true

問題3 同樣也是給你一個會議時間集合list每個元素有開始和結束時間。看看是需要會議室的最小數目

Example 1:

Input:[[0, 30],[5, 10],[15, 20]]

Output:2

Example 2:

Input:[[7,10],[2,4]]

Output:1

 

問題1 給你一個數字範圍集合list，合併重複的集合。

Example 1:

Input:[[1,3],[2,6],[8,10],[15,18]]

Output:[[1,6],[8,10],[15,18]]

Explanation:Since intervals [1,3] and [2,6] overlaps, merge them into [1,6].

Example 2:

Input:[[1,4],[4,5]]

Output:[[1,5]]

Explanation:Intervals [1,4] and [4,5] are considered overlapping.

 

問題4 就是給你一個員工的工作時間集合，找出到家共同有空的時間段。Example 1:

Input:schedule = [[[1,2],[5,6]],[[1,3]],[[4,10]]]

Output:[[3,4]]

Explanation:

There are a total of three employees, and all common

free time intervals would be [-inf, 1], [3, 4], [10, inf].

We discard any intervals that contain inf as they aren't finite.

Example 2:

Input:schedule = [[[1,3],[6,7]],[[2,4]],[[2,5],[9,12]]]

Output:[[5,6],[7,9]]