90. OCR A Level (H446) SLR14 – 1.4 Data structures part 4 – Tree

What is a tree in computer science?

• A programming language

• A data structure consisting of nodes and pointers

• A type of function

• A hardware component

Answer explanation

A tree in computer science is a data structure consisting of nodes and pointers, allowing for hierarchical organization of data.

What is at the top of a tree data structure?

• Leaf node

• Root node

• Pointer

• Edge

Answer explanation

The correct choice is the Root node, which is located at the top of a tree data structure and serves as the starting point for traversing the tree.

What are nodes at the very bottom of the tree called?

• Root nodes

• Subtrees

• Child nodes

• Leaf nodes

Answer explanation

Leaf nodes are the nodes at the very bottom of the tree, making them the correct choice for this question.

What is a binary tree?

• A tree with binary data

• A tree made of binary numbers

• A tree where each node can have zero, one, or two pointers

• A tree where each node can have up to 3 pointers

Answer explanation

A binary tree is a tree where each node can have zero, one, or two pointers, distinguishing it from trees with up to 3 pointers.

How can binary trees be represented in memory?

• As binary numbers

• Through linked lists

• With dictionaries in Python

• Using stacks

Answer explanation

Binary trees can be represented in memory using dictionaries in Python, where each node is stored as a key-value pair with references to its children nodes.

What is a common use of binary trees in computer science?

• Generating random numbers

• Database applications for efficient searching and sorting

• Designing websites

• For creating visual effects in games

Answer explanation

Binary trees are commonly used in computer science for database applications to efficiently search and sort data, making them a crucial data structure for this purpose.

What is a subtree?

• A binary tree within another binary tree

• The first half of a tree

• A set of nodes and edges from any single node down through all of its descendants

• A small tree data structure

Answer explanation

A subtree is a set of nodes and edges from any single node down through all of its descendants.

What is NOT a typical use for trees in computer science?

• Storing and managing file and folder structures

• Implementations of the A* pathfinding algorithm

• Performing arithmetic operations

• Storing and manipulating hierarchical data

Answer explanation

Performing arithmetic operations is NOT a typical use for trees in computer science. Trees are commonly used for storing and managing hierarchical data, file structures, and implementing algorithms like A* pathfinding.

How are nodes connected in a tree?

• With arrays

• With edges and pointers

• Through a network

• By binary numbers

Answer explanation

Nodes in a tree are connected with edges and pointers, allowing traversal and relationship between different nodes.

What is required for a parent node in a tree?

• It must have exactly two child nodes

• It cannot have any child nodes

• It can have zero, one, or more child nodes

• It must have at least one child node

Answer explanation

A parent node in a tree can have zero, one, or more child nodes, making it a versatile structure in tree data representation.