Find Longest Calls(LeetCode 3124):

Problem

Table: Contacts

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| id          | int     |
| first_name  | varchar |
| last_name   | varchar |
+-------------+---------+
id is the primary key (column with unique values) of this table.
id is a foreign key (reference column) to Calls table.
Each row of this table contains id, first_name, and last_name.

Table: Calls

+-------------+------+
| Column Name | Type |
+-------------+------+
| contact_id  | int  |
| type        | enum |
| duration    | int  |
+-------------+------+
(contact_id, type, duration) is the primary key (column with unique values) of this table.
type is an ENUM (category) type of ('incoming', 'outgoing').
Each row of this table contains information about calls, comprising of contact_id, type, and duration in seconds.

Write a solution to find the three longestĀ incoming and outgoing calls.

Return the result table ordered by type, duration, and first_nameĀ in descendingĀ order and duration must be formatted as HH:MM:SS.

The result format is in the following example.

Ā 

Example 1:

Input:

Contacts table:

+----+------------+-----------+
| id | first_name | last_name |
+----+------------+-----------+
| 1  | John       | Doe       |
| 2  | Jane       | Smith     |
| 3  | Alice      | Johnson   |
| 4  | Michael    | Brown     |
| 5  | Emily      | Davis     |
+----+------------+-----------+

Calls table:

+------------+----------+----------+
| contact_id | type     | duration |
+------------+----------+----------+
| 1          | incoming | 120      |
| 1          | outgoing | 180      |
| 2          | incoming | 300      |
| 2          | outgoing | 240      |
| 3          | incoming | 150      |
| 3          | outgoing | 360      |
| 4          | incoming | 420      |
| 4          | outgoing | 200      |
| 5          | incoming | 180      |
| 5          | outgoing | 280      |
+------------+----------+----------+

Output:

+-----------+----------+-------------------+
| first_name| type     | duration_formatted|
+-----------+----------+-------------------+
| Michael   | incoming | 00:07:00          |
| Jane      | incoming | 00:05:00          |
| Emily     | incoming | 00:03:00          |
| Alice     | outgoing | 00:06:00          |
| Emily     | outgoing | 00:04:40          |
| Jane      | outgoing | 00:04:00          |
+-----------+----------+-------------------+

Explanation:

  • Michael had an incoming call lasting 7 minutes.
  • Jane had an incoming call lasting 5 minutes.
  • Emily had an incoming call lasting 3 minutes.
  • Alice had an outgoing call lasting 6 minutes.
  • Emily had an outgoing call lasting 4 minutes and 40 seconds.
  • Jane had an outgoing call lasting 4 minutes.

Note: Output table is sorted by type, duration, and first_name in descending order.