Tree vs Array vs Linked List When Hierarchy Matters in DSA Javascript - Build Both Approaches

Tree vs Array vs Linked List When Hierarchy Matters

📖 Scenario: Imagine you are organizing a company's employee structure. Each employee can have subordinates, forming a hierarchy. You want to represent this hierarchy in different ways to understand how data structures like arrays, linked lists, and trees work when hierarchy matters.

🎯 Goal: You will create three data structures to represent the same employee hierarchy: an array of employees, a linked list of employees, and a tree of employees. Then, you will write code to display the hierarchy clearly.

📋 What You'll Learn

Create an array called employeesArray with employee names in order

Create a linked list called employeesLinkedList representing the same employees

Create a tree called employeesTree representing the hierarchy with subordinates

Write code to print the array, linked list, and tree hierarchy

💡 Why This Matters

🌍 Real World

Organizing company employees, file systems, or categories often needs hierarchical data structures like trees.

💼 Career

Understanding arrays, linked lists, and trees helps in software development, especially in building user interfaces, databases, and organizational tools.

1

Create an array of employees

Create an array called employeesArray with these exact employee names in order: 'CEO', 'Manager', 'Team Lead', 'Developer', 'Intern'.

DSA Javascript

# Create the array employeesArray with the given employee names
// Your code here

Hint

Use square brackets [] to create an array and put the employee names as strings inside.

2

Create a linked list of employees

Create a linked list by defining a class called Node with properties name and next. Then create nodes for each employee in this order: 'CEO', 'Manager', 'Team Lead', 'Developer', 'Intern'. Link them so that CEO points to Manager, and so on. Store the head node in a variable called employeesLinkedList.

DSA Javascript

const employeesArray = ['CEO', 'Manager', 'Team Lead', 'Developer', 'Intern'];
// Define Node class and create linked list nodes
// Your code here

Hint

Create a Node class with name and next. Then create nodes and link them by setting next properties.

3

Create a tree representing the employee hierarchy

Create an object called employeesTree representing the hierarchy: CEO is the root with one child Manager. Manager has one child Team Lead. Team Lead has two children: Developer and Intern. Use the property name for employee name and subordinates as an array of child nodes.

DSA Javascript

const employeesArray = ['CEO', 'Manager', 'Team Lead', 'Developer', 'Intern'];

class Node {
  constructor(name) {
    this.name = name;
    this.next = null;
  }
}

const ceo = new Node('CEO');
const manager = new Node('Manager');
const teamLead = new Node('Team Lead');
const developer = new Node('Developer');
const intern = new Node('Intern');

ceo.next = manager;
manager.next = teamLead;
teamLead.next = developer;
developer.next = intern;

const employeesLinkedList = ceo;

// Create employeesTree object with name and subordinates
// Your code here

Hint

Use nested objects with name and subordinates arrays to build the tree hierarchy.

4

Print the array, linked list, and tree hierarchy

Write code to print the employeesArray as a string joined by ' -> '. Then print the linked list starting from employeesLinkedList by traversing nodes and joining names with ' -> '. Finally, write a recursive function called printTree that prints the employeesTree hierarchy with indentation for subordinates. Call printTree(employeesTree, 0) to display the tree.

DSA Javascript

const employeesArray = ['CEO', 'Manager', 'Team Lead', 'Developer', 'Intern'];

class Node {
  constructor(name) {
    this.name = name;
    this.next = null;
  }
}

const ceo = new Node('CEO');
const manager = new Node('Manager');
const teamLead = new Node('Team Lead');
const developer = new Node('Developer');
const intern = new Node('Intern');

ceo.next = manager;
manager.next = teamLead;
teamLead.next = developer;
developer.next = intern;

const employeesLinkedList = ceo;

const employeesTree = {
  name: 'CEO',
  subordinates: [
    {
      name: 'Manager',
      subordinates: [
        {
          name: 'Team Lead',
          subordinates: [
            { name: 'Developer', subordinates: [] },
            { name: 'Intern', subordinates: [] }
          ]
        }
      ]
    }
  ]
};

// Print employeesArray, employeesLinkedList, and employeesTree
// Your code here

Hint

Use join(' -> ') for array, a while loop for linked list, and a recursive function with indentation for the tree.