Question

Which of the following correctly describes a binary search tree (BST)?

• A. A tree where each node has at most two children, with left child $<$ node $<$ right child
• B. A tree where each node has exactly two children
• C. A tree where all leaves are at the same level
• D. A tree where the root is the smallest value

Hint:

Understand the ordering property of BSTs for efficient searching and insertion.

Answer 1

The Correct Option is A

A binary search tree (BST) is a binary tree where:
- Each node has at most two children (left and right).
- For any node, all values in the left subtree are less than the node’s value, and all values in the right subtree are greater.
Option (1) correctly describes this.
Option (2) is incorrect as nodes can have fewer than two children.
Option (3) describes a complete binary tree, not a BST.
Option (4) is false as the root is not necessarily the smallest.