MediumNo. 2142LeetCode Premium
The Number of Passengers in Each Bus I — LeetCode 2142 Python Solution
- Topics
- Database
- Reading time
- 3 min
- Source
- leetcode.com
Table schema
Table: Buses +--------------+------+ | Column Name | Type | +--------------+------+ | bus_id | int | | arrival_time | int | +--------------+------+ bus_id is the column with unique values for this table. Each row of this table contains information about the arrival time of a bus at the LeetCode station.Example
+--------------+------+
| Column Name | Type |
+--------------+------+
| bus_id | int |
| arrival_time | int |
+--------------+------+
bus_id is the column with unique values for this table.
Each row of this table contains information about the arrival time of a bus at the LeetCode station.
No two buses will arrive at the same time.Python solution
import duckdb
import pandas as pd
def solution(buses: pd.DataFrame, passengers: pd.DataFrame) -> pd.DataFrame:
con = duckdb.connect()
con.register("Buses", buses)
con.register("Passengers", passengers)
return con.execute("""SELECT
bus_id,
COUNT(passenger_id) - LAG(COUNT(passenger_id), 1, 0) OVER (
ORDER BY b.arrival_time
) AS passengers_cnt
FROM
Buses AS b
LEFT JOIN Passengers AS p ON p.arrival_time <= b.arrival_time
GROUP BY 1
ORDER BY 1;""").df()Complexity
- Time
- O(n log n)(typical)
- Space · auxiliary
- O(n)
Related problems
| No. | Problem | Difficulty |
|---|---|---|
| 0175 | Combine Two Tables | Easy |
| 0176 | Second Highest Salary | Medium |
| 0177 | Nth Highest Salary | Medium |
| 0178 | Rank Scores | Medium |
| 0180 | Consecutive Numbers | Medium |
| 0181 | Employees Earning More Than Their Managers | Easy |
Frequently asked questions
- How hard is LeetCode 2142. The Number of Passengers in Each Bus I?
LeetCode 2142. The Number of Passengers in Each Bus I is rated Medium on LeetCode.
- What topics does LeetCode 2142. The Number of Passengers in Each Bus I cover?
LeetCode 2142. The Number of Passengers in Each Bus I is tagged Database on LeetCode.
- Is LeetCode 2142. The Number of Passengers in Each Bus I a premium problem?
Yes. LeetCode 2142. The Number of Passengers in Each Bus I is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.