Paper 1

Question 1

What is an algorithm?

Answer 1

• A sequence of steps / instructions which are followed to complete a specific task

Question 2

What is the point of pseudocode?

Answer 2

• Relaxed version of coding so that anyone can understand it

Question 3

Flowchart block shapes

Answer 3

• Oval = start / stop
• Rectangle = process
• Parallelogram = input / output
• Diamond = choice

Question 4

What is abstraction?

Answer 4

• The process of removing unnecessary detail from a problem

Question 5

What is decomposition?

Answer 5

• The process of breaking down a problem into smaller and more manageable chunks

Question 6

Explain linear search

Answer 6

• Compares each item in the list with the target item until it is found
• No need for the list to be ordered
• Simple and easy to code
• Very inefficient

Question 7

Explain binary search

Answer 7

• Compares middle item in list with target item and discards the half that it cannot be in
• Repeats finding middle item until target is found
• List must be ordered
• More complex and harder to code
• Much more effecient, especially for bigger lists

Question 8

Explain bubble sort

Answer 8

• Go in order of the list, comparing two adjacent items and putting them in the correct order
• Repeats until list is sorted
• Easy to code
• Not good for larger lists

Question 9

Explain merge sort

Answer 9

• Continously divides list until each list only has 1 item
• Combines two lists at a time, making sure that they are in order
• Repeats until whole list has been recombined and is in order
• More efficient
• Uses more memory

Question 10

What is the difference between / , DIV , MOD

Answer 10

• / = simple divide
• DIV = divide but answer is given as a whole number (no remainder / decimal)
• MOD = divide and only the remainder is returned

Question 11

What is a variable?

Answer 11

• An indentifier that holds a value that can be changed

Question 12

What are the 3 fundemental programming constructs?

Answer 12

• Sequence
• Selection
• Iteration

Question 13

Pros of using subroutines

Answer 13

• Can be reused
• Code doesn’t need to be rewritten so number of errors is decreased
• Less overall code so algorithm is more efficient

Question 14

Syntax error vs logic error

Answer 14

• Syntax error is a error in the code
• Logic error is when the code doesn’t work as expected

Question 15

Function vs procedure

Answer 15

• Function returns a value
• Procedure doesn’t