Floor and Ceil from a BST — DSA Technical Interview Questions & Answers

Floor and Ceil from a BST

Floor and Ceil from a BST

  • Floor and Ceil from a BST is a DSA topic. In plain words you use it for folder on disk in a file explorer. Don’t start with a slogan — start with that picture.
  • Smallest example: left < root < right. Type it, run it, and say what you see. If you can do that from memory, you know Floor and Ceil from a BST.
  • From the example next to this theory: Floor and Ceil from a BST — bST invariant: left < node < right — enables log-time search when balanced.
  • Trap: unbalanced BST becoming a list. Fix that before you talk about advanced DSA.
  • Viva: what is Floor and Ceil from a BST? Then show left < root < right. Then name the trap.

Technical Interview Tip: What is Floor and Ceil from a BST? Show this: left < root < right. Trap: unbalanced BST becoming a list.

Code Examples for Floor and Ceil from a BST

Floor and Ceil from a BST — working example

class Node:
    def __init__(self, val):
        self.val = val
        self.left = None
        self.right = None

def insert(root, val):
    if root is None:
        return Node(val)
    if val < root.val:
        root.left = insert(root.left, val)
    elif val > root.val:
        root.right = insert(root.right, val)
    return root

root = None
for v in [5, 2, 7, 1]:
    root = insert(root, v)
print(root.val, root.left.val, root.right.val)

Floor and Ceil from a BST — bST invariant: left < node < right — enables log-time search when balanced.

How to Explain Floor and Ceil from a BST to an Interviewer

What is Floor and Ceil from a BST?

Used for folder on disk a file explorer Not just the heading

Give one small example of Floor and Ceil from a BST.

left < root < right Floor and Ceil from a BST — bST invariant: left < node < right — enables log-time search when balanced

What mistake do beginners make with Floor and Ceil from a BST?

unbalanced BST becoming a list Show the fix

Where do you use Floor and Ceil from a BST?

a file explorer folder on disk