How hard is LeetCode 2238. Number of Times a Driver Was a Passenger?

LeetCode 2238. Number of Times a Driver Was a Passenger is rated Medium on LeetCode.

What topics does LeetCode 2238. Number of Times a Driver Was a Passenger cover?

LeetCode 2238. Number of Times a Driver Was a Passenger is tagged Database on LeetCode.

Is LeetCode 2238. Number of Times a Driver Was a Passenger a premium problem?

Yes. LeetCode 2238. Number of Times a Driver Was a Passenger is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.

Number of Times a Driver Was a Passenger — LeetCode 2238 Python Solution

MediumLeetCode PremiumDatabase

Problem: #2238
Reading time: 3 min
Source: leetcode.com

Table schema

SQL

Table: Rides +--------------+------+ | Column Name | Type | +--------------+------+ | ride_id | int | | driver_id | int | | passenger_id | int | +--------------+------+ ride_id is the column with unique values for this table. Each row of this table contains the ID of the driver and the ID of the passenger that rode in ride_id.

Example

SQL

+--------------+------+
| Column Name  | Type |
+--------------+------+
| ride_id      | int  |
| driver_id    | int  |
| passenger_id | int  |
+--------------+------+
ride_id is the column with unique values for this table.
Each row of this table contains the ID of the driver and the ID of the passenger that rode in ride_id.
Note that driver_id != passenger_id.

Python solution

Python

import duckdb
import pandas as pd

def solution(rides: pd.DataFrame) -> pd.DataFrame:
    con = duckdb.connect()
    con.register("Rides", rides)
    return con.execute("""WITH T AS (SELECT DISTINCT driver_id FROM Rides)
SELECT t.driver_id, COUNT(passenger_id) AS cnt
FROM
    T AS t
    LEFT JOIN Rides AS r ON t.driver_id = r.passenger_id
GROUP BY 1;""").df()

Complexity

Measure	Complexity
Time	O(n log n) (typical)
Space	O(n) auxiliary

Frequently asked questions

How hard is LeetCode 2238. Number of Times a Driver Was a Passenger?: LeetCode 2238. Number of Times a Driver Was a Passenger is rated Medium on LeetCode.
What topics does LeetCode 2238. Number of Times a Driver Was a Passenger cover?: LeetCode 2238. Number of Times a Driver Was a Passenger is tagged Database on LeetCode.
Is LeetCode 2238. Number of Times a Driver Was a Passenger a premium problem?: Yes. LeetCode 2238. Number of Times a Driver Was a Passenger is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.