Algorithms

Question 1

What is an algorithm?

Answer 1

An algorithm is a sequence of steps that can be followed to complete a task.

Question 2

What is decomposition?

Answer 2

Breaking a complex problem into sub problems until each task is manageable, then solving each one individually

Question 3

What is abstraction?

Answer 3

Removing unnecessary detail from a problem so you are left with important bits, simplifying the task

Question 4

What is algorithmic thinking?

Answer 4

A logical way of getting from the problem to the solution. Acknowledging if certain bits of code can be reused

Question 5

What must you always do in pseudocode?

Answer 5

Declare variables

Question 6

What is efficiency in programming?

Answer 6

How much time is needed to a run a particular algorithm and how much space is needed

Question 7

Which one is more efficient a bubble sort or a merge sort?

Answer 7

A merge sort

Splits and then merges instead of swapping each pair

Question 8

Which is more efficient binary search or a linear search?

Answer 8

Binary search
Only when list is ordered
Keeps on cutting of half rather than checking each number

Question 9

How would you address questions about abstraction?

Answer 9

1-definition
2-important detail
3-unnecessary detail

Question 10

How do you address questions about decomposition?

Answer 10

1- definition

2- two questions you can think of to sub section

Question 11

What is considered ‘time’ in programming?

Answer 11

How may number of times memory was accessed

The number of CPU cycles taken to execute the command

Question 12

is a computer program an algorithm ?

Question 13

Why use the correct data types?

Answer 13

As each data type is allocated a different amount of memory , using the correct data types makes the code more memory efficient , robust and predictable

Question 14

What is program flow ?

Answer 14

The order in which statements are executed in a program

• can be controlled used selection and iteration

Question 15

Write a pseudocode that creates a 6 digit username.
With the first 3 letters being from town first three letters
Then the second 2 digits being their current age
The last digit is the last letter of their surname

Answer 15

Question 16

Why use meaningful identifiers ?

Question 17

What are arrays ?

Answer 17

A data structure where data values of the same type are stored and defined under one variable name.

Question 18

Why are subroutines good ?

Answer 18

🔵can be tested individually making it easier to debug .
🔵can be recalled many times within the program , rather than repeating sections of code (more efficient)
🔵can be stored as separate modules and reused in other programs

Question 19

What is a local variable

Answer 19

A variable that can only be used within the structure that they have been declared .
✅cannot and are not affected by anything outside a subroutine (same variable name can be used elsewhere )
✅✅