1.4 - Data types, Data Structures and Algorithms (Unfinished)

Question 1

Worded Effect of Bitwise Mask: AND

Answer 1

• EXTRACTS a subset of the bits in the value; when the mask is 1, you are copying the original binary sequence and when the mask is 0, you are blanking it.

Question 2

Worded Effect of Bitwise Mask: OR

Answer 2

• Can SET a subset of the bits in the value; when the mask is 1, sets value to 1 and when the mask is 0, you are leaving it alone.

Question 3

Worded Effect of Bitwise Mask: XOR

Answer 3

• TOGGLES a subset of the bits in the value: when the mask is 1, the value is changed (“toggled”) and when the mask is 0, the value stays the same

Question 4

Output of values in instances of Bitwise Mask: AND

Answer 4

• If both values are 1: Output = 1
• If not: Output = 0

Question 5

Output of values in instances of Bitwise Mask: OR

Answer 5

• If either the value or the mask is 1: Output = 1
• If both are 0: Output = 0

Question 6

Output of values in instances of Bitwise Mask: XOR

Answer 6

• If the value and the mask are different (one is 0 and the other is 1): Output is 1
• If the value and the mask are the same (both 0 or both 1): Output is 0

Question 7

What is a Character Set?

Answer 7

• The characters or symbols that can be recognised, represented, interpreted, understood and used by a computer.
• Each required character is represented by a unique binary code or number so each symbol is distinguishable from
  all others.

Question 8

Similarities between ASCII and Unicode

Answer 8

• Both use binary to represent characters / are character sets
• The first 7/8 bits of Unicode is the same as ASCII (overlaps)

Question 9

Differences between ASCII and Unicode

Answer 9

• ASCII has fewer characters (128/256); Unicode has more characters
• ASCII is 7/8 bits whereas Unicode can be larger (16/32 bits) and can have variable sized characters
• ASCII limited to Latin / English / European characters whereas Unicode can represent other symbols (e.g. Chinese/Emojis)

Question 10

What does ASCII stand for?

Answer 10

American Standard Code for Information Interchange

Question 11

Describe an Array

Answer 11

A static data structure that holds multiple pieces of data (of the same data type) contiguously in memory with a single identifier

Question 12

Dimensions of Arrays

Answer 12

• 1D Array - A single set of data, which can be visualised in a single row
• 2D Array - A set of data that can visualised in rows and columns; items are called by [Row Num. , Column Num.]
• 3D Array - A collection of 2D Arrays that can be visualised one behind the other; items are called by [2D Array Num. , Row Num. , Column Num.]

Question 13

Describe a Record

Answer 13

• Can store multiple values under one identifier
• The data can be of different data types

Question 14

Describe a List

Answer 14

• A mutable collection of items that can store more than one data type
• Size is not fixed and items can be changed or replaced
• [] in Python

Question 15

Describe a Tuple

Answer 15

• An immutable collection of items that can store more than one data type
• Size is fixed and items cannot be changed or replaced
• () in Python

Question 16

Static vs.Dynamic

Answer 16

• Static - A data structure whose size cannot be changed at runtime
• Dynamic - A data structure whose size can be changed at runtime

Question 17

Mutable vs. Immutable

Answer 17

• Mutable - Its structure and the data it contains can be changed at runtime
• Immutable - Its structure and the data it contains cannot be changed at runtime

Question 18

Describe a Linked List

Answer 18

A dynamic data structure where each node consists of data and a pointer that gives location of next node

Question 19

Describe a Graph

Answer 19

• A collection of data nodes with connections () set between them
• Graphs (edges) can be directed (directional or bi-directional) or can undirected
• Graphs can also be weighted to show relationships between nodes such as distance

Question 20

Describe a Stack

Answer 20

• A dynamic Last In First Out (LIFO) data structure; data is added to (Pushed) and removed (Popped) from the top of the stack
• There are 2 pointers: a top (often called ‘Stack Pointer’) and a bottom

Question 21

Describe a Queue

Answer 21

• A linear and dynamic First in First Out (FIFO) data structure; data is removed (dequeued) from the front of the queue and added (enqueued) to the back of the queue
• There are 2 pointers: a top and a bottom

Question 22

Describe a Tree

Answer 22

• A non linear and dynamic branching data structure that consists of a Root Node and sub nodes that are connected by edges
• Trees are 1 directional and unweighted

Question 23

Describe a Binary Search Tree

Answer 23

• A specific kind of tree where each node can only have a maximum of 2 children nodes