Find the Subtasks That Did Not Execute — LeetCode 1767 Python Solution

Table: Tasks +----------------+---------+ | Column Name | Type | +----------------+---------+ | task_id | int | | subtasks_count | int | +----------------+---------+ task_id is the column with unique values for this table. Each row in this table indicates that task_id was divided into subtasks_count subtasks labeled from 1 to subtasks_count.

+----------------+---------+
| Column Name    | Type    |
+----------------+---------+
| task_id        | int     |
| subtasks_count | int     |
+----------------+---------+
task_id is the column with unique values for this table.
Each row in this table indicates that task_id was divided into subtasks_count subtasks labeled from 1 to subtasks_count.
It is guaranteed that 2 <= subtasks_count <= 20.

import duckdb
import pandas as pd

def solution(tasks: pd.DataFrame, executed: pd.DataFrame) -> pd.DataFrame:
    con = duckdb.connect()
    con.register("Tasks", tasks)
    con.register("Executed", executed)
    return con.execute("""WITH RECURSIVE
    T(task_id, subtask_id) AS (
        SELECT
            task_id,
            subtasks_count
        FROM Tasks
        UNION ALL
        SELECT
            task_id,
            subtask_id - 1
        FROM t
        WHERE subtask_id > 1
    )
SELECT
    T.*
FROM
    T
    LEFT JOIN Executed USING (task_id, subtask_id)
WHERE Executed.subtask_id IS NULL;""").df()