# 2.1 – Algorithms Flashcards

1
Q

What is abstraction?

A
• Removing unnecessary details and including only the relevant ones
• Focuses on what is important in problem solving
2
Q

What is decomposition?

A
• Breaking down a complex problem into small, more manageable parts
• Makes problems easier to solve & different people can work on different parts of a problem at the same time
3
Q

What is algorithmic thinking?

A
• Getting to a solution by identifying the steps needed
• Can allow a solution to be automated
4
Q

What is an algoritm?

A

A sequence of steps designed to perform a particular task

5
Q

What is an input?

A

Data that is entered into or received by a computer

6
Q

What is a process?

A

A program that is running in a computer

7
Q

What is an output?

A

How to computer presents the result of a process

8
Q

What is a flow diagram?

A

A method of designing algorithms before coding using symbols

9
Q

What is a structure diagram?

A

A diagram that illustrates problem decomposition, produced using a method known as step-wise refinement

10
Q

How do structure diagrams work?

A
• Decompose the problem; some areas will need more breaking down than others
• Lowest level nodes should achieve a single task which can then be coded as a single module or sub-program
11
Q

What is Pseudocode?

A

An alternative, text-based way of representing the sequence of steps in an algorithm (simplified programming code)
Has no defined syntax so cannot be compiled or interpreted by the computer

12
Q

What does Pseudocode do?

A

Lays down the logic of a program in an almost “real code” way without worrying about actual rules & syntax or an actual language

13
Q

What is a Binary Search?

A

Accessing the middle record and determining whether the data item has been found
If not, checking whether it is before or after the current record in the data set
Discarding the half of the data set that does not contain the record in each pass
Repeating the algorithm until the data item is found or it is not in the data set
It only works if records in the file are in sequence

14
Q

What is a Bubble Sort?

A

Repeatedly steps through a data set comparing each pair of adjacent items
Swaps pairs of items if they are in the wrong order
Stops when no swaps are made

15
Q

What is an Insertion Sort?

A

Finds the correct location in a list for an item…
…By comparing it to the other items in the list in a linear way…
…Inserting the new item at the correct position…
…By moving all the other items after it by one index

16
Q

What is a Linear Search?

A

Examining each data item in turn, starting from index number 0, until the item is found or the end of the data structure / file is reached

17
Q

What is a Merge Sort?

A

A divide and conquer algorithm
A list is repeatedly divided into smaller lists eventually containing just one item.
Each element is compared with the adjacent list…
…And merged back together from two lists into one