Choosing the right data structure in Intro to Computing - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a data structure?

A data structure is a way to organize and store data so it can be used efficiently, like how a bookshelf organizes books for easy finding.

beginner

Why is choosing the right data structure important?

Choosing the right data structure helps your program run faster and use less memory, just like choosing the right container helps you carry things easily.

beginner

Which data structure is best for fast lookup by key?

A dictionary (or map) is best for fast lookup by key, like a phone book where you find a number by a person's name quickly.

beginner

When should you use a list (array)?

Use a list when you want to keep items in order and access them by position, like a line of people waiting where you know who is first or last.

beginner

What is a real-life analogy for a stack data structure?

A stack is like a stack of plates: you add or remove plates only from the top, following last-in, first-out (LIFO) order.

Which data structure is best for storing unique items without order?

A Set

B List

C Queue

D Stack

A set stores unique items and does not keep them in order, like a collection of unique stamps.

If you need to process items in the order they arrive, which data structure should you use?

A Stack

B Tree

C Dictionary

D Queue

A queue processes items in first-in, first-out (FIFO) order, like a line at a store.

Which data structure allows fast access to elements by index?

A Set

B Dictionary

C List (Array)

D Graph

Lists or arrays allow fast access by position, like knowing the 3rd book on a shelf.

What is the main advantage of using a dictionary (map)?

A Fast lookup by key

B Stores unique items only

C Keeps items in order

D Processes items in FIFO order

Dictionaries provide fast lookup by key, like finding a contact by name.

Which data structure is like a stack of plates?

A Queue

B Stack

C Set

D List

A stack follows last-in, first-out (LIFO), like adding/removing plates from the top.

Explain how you would choose a data structure for storing a list of tasks to do in order.

Think about how you handle a to-do list or waiting line.

Describe a real-life example for when a dictionary (map) is the best data structure to use.

Think about looking up someone's phone number by their name.