All people report to the given manager

# Table: Employees
# 
# +---------------+---------+
# | Column Name   | Type    |
# +---------------+---------+
# | employee_id   | int     |
# | employee_name | varchar |
# | manager_id    | int     |
# +---------------+---------+
# employee_id is the column of unique values for this table.
# Each row of this table indicates that the employee with ID employee_id and name employee_name reports his work to his/her direct manager with manager_id
# The head of the company is the employee with employee_id = 1.
# 
#  
# 
# Write a solution to find employee_id of all employees that directly or indirectly report their work to the head of the company.
# 
# The indirect relation between managers will not exceed three managers as the company is small.
# 
# Return the result table in any order.
# 
# The result format is in the following example.
#
# Example 1:
# Input:
# Employees table:
# +-------------+---------------+------------+
# | employee_id | employee_name | manager_id |
# +-------------+---------------+------------+
# | 1           | Boss          | 1          |
# | 3           | Alice         | 3          |
# | 2           | Bob           | 1          |
# | 4           | Daniel        | 2          |
# | 7           | Luis          | 4          |
# | 8           | Jhon          | 3          |
# | 9           | Angela        | 8          |
# | 77          | Robert        | 1          |
# +-------------+---------------+------------+
# Output:
# +-------------+
# | employee_id |
# +-------------+
# | 2           |
# | 77          |
# | 4           |
# | 7           |
# +-------------+
# Explanation:
# The head of the company is the employee with employee_id 1.
# The employees with employee_id 2 and 77 report their work directly to the head of the company.
# The employee with employee_id 4 reports their work indirectly to the head of the company 4 --> 2 --> 1.
# The employee with employee_id 7 reports their work indirectly to the head of the company 7 --> 4 --> 2 --> 1.
# The employees with employee_id 3, 8, and 9 do not report their work to the head of the company directly or indirectly.

import pandas as pd

def find_reporting_people(employees: pd.DataFrame) -> pd.DataFrame:
  manager_map = employees.set_index('employee_id')['manager_id'].to_dict()
  result = []
  for eid in employees['employee_id']:
    if eid == 1:
      continue
    curr = eid
    for _ in range(3):
      curr = manager_map.get(curr)
      if curr is None:
        break
      if curr == 1:
        result.append(eid)
        break
  return pd.DataFrame({'employee_id': result})