BST Find Maximum Element in DSA Javascript - Build from Scratch

BST Find Maximum Element

📖 Scenario: You are working with a Binary Search Tree (BST) that stores numbers. In a BST, all numbers to the left of a node are smaller, and all numbers to the right are larger. You want to find the largest number stored in this tree.

🎯 Goal: Build a small program that creates a BST, then finds and prints the maximum number stored in it.

📋 What You'll Learn

Create a BST with the exact numbers: 15, 10, 20, 8, 12, 17, 25

Create a variable called current to help find the maximum element

Use a while loop to move to the rightmost node in the BST

Print the maximum value found in the BST

💡 Why This Matters

🌍 Real World

Finding the maximum value in a BST is useful in many applications like databases, search engines, and file systems where data is stored in sorted order.

💼 Career

Understanding BST operations like finding maximum values is important for software developers working with data structures, algorithms, and performance optimization.

1

Create the BST nodes

Create a class called Node with a constructor that takes value and sets left and right to null. Then create the root node called root with value 15. Add the following nodes to build the BST exactly as shown: 10, 20, 8, 12, 17, 25. Connect them properly to form the BST.

DSA Javascript

// Create Node class and root node
// Your code here

Hint

Remember, each node has a value and two children: left and right. Connect nodes so smaller values go left, larger go right.

2

Set up a variable to find the maximum

Create a variable called current and set it equal to root. This will help you move through the tree to find the maximum value.

DSA Javascript

class Node {
  constructor(value) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

const root = new Node(15);
root.left = new Node(10);
root.right = new Node(20);
root.left.left = new Node(8);
root.left.right = new Node(12);
root.right.left = new Node(17);
root.right.right = new Node(25);

// Create variable current and set it to root
// Your code here

Hint

Use let current = root; to start at the root node.

3

Find the maximum value by moving right

Use a while loop with the condition current.right !== null. Inside the loop, update current to current.right. This will move current to the rightmost node, which holds the maximum value.

DSA Javascript

class Node {
  constructor(value) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

const root = new Node(15);
root.left = new Node(10);
root.right = new Node(20);
root.left.left = new Node(8);
root.left.right = new Node(12);
root.right.left = new Node(17);
root.right.right = new Node(25);

let current = root;

// Use a while loop to move current to the rightmost node
// Your code here

Hint

Keep moving current to the right child until there is no right child left.

4

Print the maximum value

Print the maximum value found in the BST by writing console.log(current.value).

DSA Javascript

class Node {
  constructor(value) {
    this.value = value;
    this.left = null;
    this.right = null;
  }
}

const root = new Node(15);
root.left = new Node(10);
root.right = new Node(20);
root.left.left = new Node(8);
root.left.right = new Node(12);
root.right.left = new Node(17);
root.right.right = new Node(25);

let current = root;

while (current.right !== null) {
  current = current.right;
}

// Print the maximum value
// Your code here

Hint

Use console.log(current.value) to show the maximum number.