BST Find Maximum Element in DSA Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Binary Search Tree (BST)?

A Binary Search Tree is a tree where each node has at most two children. The left child's value is less than the parent's value, and the right child's value is greater than the parent's value.

beginner

In a BST, where is the maximum element located?

The maximum element is always found at the rightmost node because values increase as you move right.

beginner

Why do we keep moving right to find the maximum element in a BST?

Because in a BST, all right children have values greater than their parents, so the farthest right node holds the largest value.

intermediate

What is the time complexity to find the maximum element in a BST?

The time complexity is O(h), where h is the height of the tree. In the worst case (skewed tree), it can be O(n).

beginner

Show the JavaScript code snippet to find the maximum element in a BST.

function findMax(root) {
  if (!root) return null;
  while (root.right) {
    root = root.right;
  }
  return root.value;
}

Where do you find the maximum element in a BST?

A Leftmost node

B Rightmost node

C Root node

D Any leaf node

The maximum element is always at the rightmost node in a BST.

What is the first step to find the maximum element in a BST?

A Go to the right child

B Go to the left child

C Check the root value

D Traverse all nodes

You start by moving to the right child repeatedly to find the maximum.

What is the time complexity to find the maximum element in a balanced BST?

A O(1)

B O(n log n)

C O(log n)

D O(n)

In a balanced BST, height h is about log n, so time complexity is O(log n).

If a BST has only one node, what is the maximum element?

A The right child value

B No maximum element

C The left child value

D The root node's value

With one node, the root itself is the maximum element.

What happens if you call findMax on an empty BST?

A Returns null

B Returns 0

C Throws error

D Returns undefined

The function returns null when the BST is empty.

Explain how to find the maximum element in a Binary Search Tree.

Think about where larger values are stored in a BST.

Write a simple JavaScript function to find the maximum value in a BST and explain its steps.

Use a while loop to traverse right children.