Data Types, Data structures and algorithms 1.4

Question 1

What data type should be used for storing a phone number?

Answer 1

String - if stored as an integer this would remove the zero at the start of the number

Question 2

What is an Array?

Answer 2

An ordered, finite set of elements of a single type

Question 3

How can you visualize a two-dimensional array?

Answer 3

A spreadsheet or table

Question 4

How can you visualize a three-dimensional array?

Answer 4

A three dimensional array can be visualized as a multipage

Question 5

What is a record?

Answer 5

A row in a file

Question 6

What is a record made up of?

Answer 6

A record is made up of fields

Question 7

What is the definition of a list?

Answer 7

A data structure consisting of a number of items. Items can appear more than once

Question 8

What are the main differences between an array and a list?

Answer 8

1. List can store data Non-contiguously whereas arrays store data in order
2. List can store many data types

Question 9

What is a tuple?

Answer 9

An immutable, ordered set of values of any type

Question 10

What is the difference between a tuple and an array?

Answer 10

Tuples use normal brackets instead of square brackets

Question 11

What is a linked list?

Answer 11

A linked list is a dynamic data structure used to hold an ordered set of items that are not stored in contiguous locations.

Question 12

What is the name of an item in a linked list?

Answer 12

Nodes

Question 13

What does each node in a linked list contain?

Answer 13

each node contains its data and the address of the next node

Question 14

What is a stack?

Answer 14

A LIFO data structure where items can only be removed and added on the top of the stack

LIFO = Last in First out

Question 15

Give an example of when a stack may be used

Answer 15

Back button in a web page

Question 16

What is a queue?

Answer 16

A FIFO data structure where items are added to the back of the queue and removed from the front

FIFO = First in first out

Question 17

What is a Tree?

Answer 17

A data structure with a root node and a child node connected with branches

Question 18

What is the purpose of a binary search tree?

Answer 18

A binary search tree is used to search for values quickly

Question 19

What is a Hash Table?

Answer 19

A hash table is an array which is coupled with a hash function. The hash function takes in data (a key) and releases an output (the hash). The role of the hash function is to map the key to an index in the hash table.

Question 20

What is a collision? (hashing)

Answer 20

A collision is when two inputs result in the same hash value

Question 21

What properties does a good hashing algorithm have?

Answer 21

1. Low chance of collision
2. Fast

Question 22

What does the operation isEmpty() do?

Answer 22

Checks if the list is empty

Question 23

What does the operation pop() do?

(Stack)

Answer 23

takes out the last item in the stack out

Question 24

What does the operation Push(value) do?

(Stack)

Answer 24

It adds the value to the top of the stack

Question 25

What does the operation peek() do?

(Stack)

Answer 25

Returns the top value of the stack

Question 26

What does the operation isFull() do

(Stack)

Answer 26

Checks if the stack is full

Question 27

What does the operation size() do

(stack)

Answer 27

Returns the size of the stack

Question 28

What does the operation enQueue do

Answer 28

Add a item to the back of the queue

Question 29

1. What does the operation deQueue() do?

Answer 29

Removes the item from the end of the queue

Question 30

Add questions of hash(maps)