Rolling Average Steps — LeetCode 2854 Python Solution

MediumLeetCode PremiumDatabase
Problem
#2854
Reading time
7 min

Table schema

SQL
Table: Steps +-------------+------+ | Column Name | Type | +-------------+------+ | user_id | int | | steps_count | int | | steps_date | date | +-------------+------+ (user_id, steps_date) is the primary key for this table. Each row of this table contains user_id, steps_count, and steps_date.

Example

SQL
+-------------+------+ 
| Column Name | Type | 
+-------------+------+ 
| user_id     | int  | 
| steps_count | int  |
| steps_date  | date |
+-------------+------+
(user_id, steps_date) is the primary key for this table.
Each row of this table contains user_id, steps_count, and steps_date.

Python solution

Python
import duckdb
import pandas as pd

# Pass input tables as keyword arguments matching the SQL table names.
def solution(**tables) -> pd.DataFrame:
    con = duckdb.connect()
    for name, df in tables.items():
        con.register(name, df)
    return con.execute("""WITH
    T AS (
        SELECT
            user_id,
            steps_date,
            ROUND(
                AVG(steps_count) OVER (
                    PARTITION BY user_id
                    ORDER BY steps_date
                    ROWS 2 PRECEDING
                ),
                2
            ) AS rolling_average,
            DATEDIFF(
                steps_date,
                LAG(steps_date, 2) OVER (
                    PARTITION BY user_id
                    ORDER BY steps_date
                )
            ) = 2 AS st
        FROM Steps
    )
SELECT
    user_id,
    steps_date,
    rolling_average
FROM T
WHERE st = 1
ORDER BY 1, 2;""").df()

Complexity

MeasureComplexity
TimeO(n log n) (typical)
SpaceO(n) auxiliary

Related problems

Frequently asked questions

How hard is LeetCode 2854. Rolling Average Steps?
LeetCode 2854. Rolling Average Steps is rated Medium on LeetCode.
What topics does LeetCode 2854. Rolling Average Steps cover?
LeetCode 2854. Rolling Average Steps is tagged Database on LeetCode.
Is LeetCode 2854. Rolling Average Steps a premium problem?
Yes. LeetCode 2854. Rolling Average Steps is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.

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