Binary Tree Node Structure in DSA Typescript - Build from Scratch

Binary Tree Node Structure

📖 Scenario: You are building a simple binary tree to store numbers. Each spot in the tree can hold one number and can have up to two smaller spots connected to it: one on the left and one on the right.

🎯 Goal: Create a basic binary tree node structure in TypeScript. You will first define the node with its value and connections, then create a simple tree with three nodes.

📋 What You'll Learn

Define a class called TreeNode with three properties: value, left, and right.

The value should be a number.

The left and right should be either another TreeNode or null.

Create three nodes with values 10, 5, and 15.

Connect the nodes so that 10 is the root, 5 is the left child, and 15 is the right child.

💡 Why This Matters

🌍 Real World

Binary trees are used in many applications like searching, sorting, and organizing data efficiently.

💼 Career

Understanding binary tree structures is fundamental for software developers working with data structures, algorithms, and system design.

1

Define the TreeNode class

Create a class called TreeNode with a constructor that takes a value of type number. Inside the constructor, set this.value to the given value. Also, add two properties left and right initialized to null.

DSA Typescript

class TreeNode {
  value: number;
  left: TreeNode | null;
  right: TreeNode | null;

  constructor(value: number) {
    // Your code here
  }
}

Hint

Remember to set this.value to the input value. Initialize left and right to null.

2

Create three TreeNode instances

Create three variables called root, leftChild, and rightChild. Assign them new TreeNode objects with values 10, 5, and 15 respectively.

DSA Typescript

class TreeNode {
  value: number;
  left: TreeNode | null;
  right: TreeNode | null;

  constructor(value: number) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

// Create three TreeNode instances
// Your code here

Hint

Use new TreeNode(value) to create each node and assign to the correct variable.

3

Connect the nodes to form the tree

Set the left property of root to leftChild and the right property of root to rightChild.

DSA Typescript

class TreeNode {
  value: number;
  left: TreeNode | null;
  right: TreeNode | null;

  constructor(value: number) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

const root = new TreeNode(10);
const leftChild = new TreeNode(5);
const rightChild = new TreeNode(15);

// Connect root to leftChild and rightChild
// Your code here

Hint

Use dot notation to set root.left and root.right.

4

Print the tree node values

Print the values of root, root.left, and root.right using console.log. Print them in this order, separated by spaces.

DSA Typescript

class TreeNode {
  value: number;
  left: TreeNode | null;
  right: TreeNode | null;

  constructor(value: number) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

const root = new TreeNode(10);
const leftChild = new TreeNode(5);
const rightChild = new TreeNode(15);

root.left = leftChild;
root.right = rightChild;

// Print the values of root, root.left, and root.right
// Your code here

Hint

Use console.log(root.value, root.left?.value, root.right?.value) to print the values separated by spaces.