Workforce Chain to Company Head

Medium

A company keeps reporting-line data in a single relational table: Employees(employee_id, employee_name, manager_id) Column details: employee_id: unique employee identifier employee_name: display name manager_id: direct manager's employee_id Business rules: The company head has employee_id = 1. Every employee reports to exactly one direct manager. Reporting can be direct (one hop) or indirect (multiple hops). Task: Return the employee_id of every employee who reports to the company head (employee_id = 1), either directly or indirectly. Output requirements: Return exactly one column named employee_id. Do not include employee_id = 1 in the output. Return rows in any order. Supported submission environments: SQL (SQLite 3.27.2) Pandas (Python)

Example 1

Input

employees:
| employee_id | employee_name | manager_id |
|-------------|---------------|------------|
| 1           | CEO           | 1          |
| 2           | Nora          | 1          |
| 3           | Omar          | 3          |
| 4           | Priya         | 2          |
| 5           | Quentin       | 4          |
| 6           | Rina          | 6          |
| 7           | Sam           | 3          |

Output

[
  {"employee_id":2},
  {"employee_id":4},
  {"employee_id":5}
]

Explanation

Employees 2, 4, and 5 are in the reporting chain that reaches employee 1. Employees 3, 6, and 7 are outside that chain.

Example 2

Input

employees:
| employee_id | employee_name | manager_id |
|-------------|---------------|------------|
| 1           | CEO           | 1          |
| 9           | Tina          | 9          |
| 10          | Uma           | 9          |

Output

[]

Explanation

No employee has a manager chain that reaches employee 1.

Example 3

Input

employees:
| employee_id | employee_name | manager_id |
|-------------|---------------|------------|
| 1           | CEO           | 1          |
| 11          | Vik           | 1          |
| 12          | Wen           | 11         |
| 13          | Xena          | 12         |
| 14          | Yara          | 14         |

Output

[
  {"employee_id":11},
  {"employee_id":12},
  {"employee_id":13}
]

Explanation

Employees 11, 12, and 13 connect to employee 1 through a direct/indirect chain. Employee 14 is self-managed and does not report to 1.

Constraints

1 <= number of rows in employees <= 100000
employee_id is unique
employee_id = 1 represents the company head
manager_id is an integer employee identifier
An employee may belong to a component that does not reach employee 1
Return exactly one column: employee_id
Exclude employee_id = 1 from output
Use SQLite 3.27.2 semantics for SQL submissions
For Pandas submissions, return a DataFrame with exactly one column named employee_id

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Workforce Chain to Company Head

Medium

A company keeps reporting-line data in a single relational table: Employees(employee_id, employee_name, manager_id) Column details: employee_id: unique employee identifier employee_name: display name manager_id: direct manager's employee_id Business rules: The company head has employee_id = 1. Every employee reports to exactly one direct manager. Reporting can be direct (one hop) or indirect (multiple hops). Task: Return the employee_id of every employee who reports to the company head (employee_id = 1), either directly or indirectly. Output requirements: Return exactly one column named employee_id. Do not include employee_id = 1 in the output. Return rows in any order. Supported submission environments: SQL (SQLite 3.27.2) Pandas (Python)

Example 1

Input

employees:
| employee_id | employee_name | manager_id |
|-------------|---------------|------------|
| 1           | CEO           | 1          |
| 2           | Nora          | 1          |
| 3           | Omar          | 3          |
| 4           | Priya         | 2          |
| 5           | Quentin       | 4          |
| 6           | Rina          | 6          |
| 7           | Sam           | 3          |

Output

[
  {"employee_id":2},
  {"employee_id":4},
  {"employee_id":5}
]

Explanation

Employees 2, 4, and 5 are in the reporting chain that reaches employee 1. Employees 3, 6, and 7 are outside that chain.

Example 2

Input

employees:
| employee_id | employee_name | manager_id |
|-------------|---------------|------------|
| 1           | CEO           | 1          |
| 9           | Tina          | 9          |
| 10          | Uma           | 9          |

Output

[]

Explanation

No employee has a manager chain that reaches employee 1.

Example 3

Input

employees:
| employee_id | employee_name | manager_id |
|-------------|---------------|------------|
| 1           | CEO           | 1          |
| 11          | Vik           | 1          |
| 12          | Wen           | 11         |
| 13          | Xena          | 12         |
| 14          | Yara          | 14         |

Output

[
  {"employee_id":11},
  {"employee_id":12},
  {"employee_id":13}
]

Explanation

Employees 11, 12, and 13 connect to employee 1 through a direct/indirect chain. Employee 14 is self-managed and does not report to 1.

Constraints

1 <= number of rows in employees <= 100000
employee_id is unique
employee_id = 1 represents the company head
manager_id is an integer employee identifier
An employee may belong to a component that does not reach employee 1
Return exactly one column: employee_id
Exclude employee_id = 1 from output
Use SQLite 3.27.2 semantics for SQL submissions
For Pandas submissions, return a DataFrame with exactly one column named employee_id