problem set.md

Employee Hierarchies Problem Set

This problem set explores a number of questions related to a company and its employees; specifically, its hierarchy of management:

const employees = [
  { name: 'Alice',  manager: null,    title: 'CEO' },
  { name: 'Bob',    manager: 'Alice', title: 'Head of Marketing' },
  { name: 'Carol',  manager: 'Alice', title: 'Head of Engineering' },
  { name: 'Darcy',  manager: 'Carol', title: 'Systems Architect' },
  { name: 'Edwin',  manager: 'Bob',   title: 'SEO Specialist' },
  { name: 'Farah',  manager: 'Carol', title: 'Senior Developer' },
  { name: 'Georg',  manager: 'Carol', title: 'Junior Developer' }
];

1. Write a function that takes the employee list and outputs the number of direct reports each employee has. For this dataset, the output would be:

   {
     'Alice': 2,
     'Bob': 1,
     'Carol': 3,
     'Darcy': 0,
     'Edwin': 0,
     'Farah': 0,
     'Georg': 0
   }

2. Write a function that takes the employee list and outputs another array that contains an array of the names of an employee's direct reports instead of their manager's name, e.g.:

   [
     { name: 'Alice', reports: ['Bob', 'Carol'], title: 'CEO' },
     ...
   ]

3. Modify the function from #2 to include indirect reports, too; i.e. if Alice is Bob's manager and Bob is Edwin's manager, Edwin is one of Alice's indirect reports.

4. Write a function that takes the employee list and returns the depth of the employee hierarchy at the company. For this company, the depth is 3. A completely flat hierarchy (no managers) has a depth of 1.

5. Suppose we were to change the dataset slightly and change Alice's manager to Darcy:

   { name: 'Alice', manager: 'Darcy', title: 'CEO (???)' }

   What would happen if you ran the code you wrote in #3 and #4? What is this type of error called? Write a function to detect if the dataset contains any of these problems, returning true if the dataset is invalid (contains any of these problems) and false otherwise.