Managers with at Least 5 Direct Reports — LeetCode 570 Python Solution

The problem

Find the names of the managers who have at least five employees reporting directly to them. The Employee table has id (int, primary key), name (varchar), department (varchar) and managerId (int), which is null when the employee has no manager, and nobody manages themselves. Return the names in a column called name.

Example

Input

Employee(id, name, department, managerId) = (101, 'Nia', 'Engineering', null), (102, 'Omar', 'Engineering', 101), (103, 'Pia', 'Engineering', 101), (104, 'Raj', 'Engineering', 101), (105, 'Sam', 'Engineering', 101), (106, 'Tess', 'Engineering', 101), (107, 'Uma', 'Sales', 102)

Output

name = 'Nia'

Explanation

Ids 102 to 106 report to 101, so Nia has five direct reports; Omar has only one.

Python solution

import pandas as pd


def find_managers(employee: pd.DataFrame) -> pd.DataFrame:
    # Group the employees by managerId and count the number of direct reports
    manager_report_count = (
        employee.groupby("managerId").size().reset_index(name="directReports")
    )

    # Filter managers with at least five direct reports
    result = manager_report_count[manager_report_count["directReports"] >= 5]

    # Merge with the Employee table to get the names of these managers
    result = result.merge(
        employee[["id", "name"]], left_on="managerId", right_on="id", how="inner"
    )

    # Select only the 'name' column and drop the 'id' and 'directReports' columns
    result = result[["name"]]

    return result

Complexity

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