7 Algorithm design and problem solving

Question 1

What are some different types of programming languages?

Answer 1

Declarative, object-oriented, event driven, procedural

Question 2

What is a declarative programming language?

Answer 2

Language where rules are declared, you can ask questions, answer given based upon the rules

Question 3

What is an object-oriented programming language?

Answer 3

Language where user can create objects that have attributes and methods

Question 4

What is an event driven programming language?

Answer 4

A language where there are buttons, text boxes and items user can interact with, each item has its own code which is only run when the item is clicked or changed, all code of program not run from start to finsih

Question 5

What is a procedural programming language?

Answer 5

Language with statements run in order they are written in, uses subroutines which can be called from other parts of the program

Question 6

What is the program development life cycle?

Answer 6

A series of structured steps followed to produce a system

Question 7

What are some different varieties of the program development life cycle?

Answer 7

Cyclic, spiral, waterfall and rapid development

Question 8

What are the stages of the program development life cycle?

Answer 8

Analysis, design, coding and testing

Question 9

What is decomposition?

Answer 9

The process of taking a problem or system, and splitting it into smaller parts (sub-problems, sub-systems) which it turn can be split into smaller parts

Question 10

What is the analysis stage of the program development life cycle?

Answer 10

The first stage of the cycle where the problem is investigated

Question 11

What is the design stage of the program development life cycle?

Answer 11

The second stage of the cycle where the program is planned out and the problem is decomposed

Question 12

What things can be used in the design stage of the program development life cycle to plan out the program?

Answer 12

Structure diagram, flowcharts and pseudocode

Question 13

What is a structure diagram?

Answer 13

A hierarchical diagram that shows a decomposed system, the name of the program at the top and its subprograms below

Question 14

What is a flowchart?

Answer 14

A diagrammatic representation of an algorithm with symbols for decisions, processes, start / stop points and arrows to show the direction of flow

Question 15

In a flowchart, how is the content inside each box written?

Answer 15

Written as words or pseudocode statements

Question 16

In a flowchart, what is the symbol for a each thing?

Answer 16

Start / stop - curved rectangle thing, process - rectangle, input / output - parallelogram, decision - diamond (think)

Question 17

What is pseudocode?

Answer 17

Code-like statements used to design an algorithm but do not follow any specific language

Question 18

What is important in pseudocode and what can be imperfect?

Answer 18

Logic is important, syntax can be imperfect

Question 19

What is the coding stage of the program development life cycle?

Answer 19

The third stage of the cycle where a program is written in a programming language, includes iterative testing while program is being developed

Question 20

What is the testing stage of the program development life cycle?

Answer 20

The fourth stage of the cycle where a program is repeatedly used with test data to ensure it fully works, doesn’t crash and meets all requirements

Question 21

What are the four types of test data and what are their details?

Answer 21

Normal - data program should accept, abnormal - data program shouldn’t accept, extreme - data on edge of what is accepted, boundary - data on edge of being accepted and rejected

Question 22

What is a search algorithm?

Answer 22

An algorithm which checks a set of data to see if a specific value exists in it or not

Question 23

What is a sorting algorithm?

Answer 23

An algorithm which takes a set of data and rearranges it to be in a specific order

Question 24

What is linear search?

Answer 24

A search algorithm which checks each item one at a time, and keeps continuing to the next item until it finds the data it is searching for or reaches the end

Question 25

What is bubble sort?

Answer 25

A sorting algorithm which takes values 1 and 2, swaps them if they are the wrong way round, checks values 2 and 3, and repeats for the entire list.

Question 26

How does a bubble sort algorithm stop?

Answer 26

If the number of times the algorithm has been through the list = the number of elements in the list - 1, or if the algorithm has been through the list without making any changes

Question 27

What are some number-related things program can do?

Answer 27

Totalling, counting, finding the minimum, finding the maximum, finding the average (can be mean)

Question 28

What is validation in computer science?

Answer 28

The checking of data to make sure it is reasonable and within set bounds

Question 29

What are some types of validation?

Answer 29

Range check (checks if data within one or two numeric bounds), length check (checks number of characters within set limit), type check (checks data is the correct type), presence check (checks if data has been entered), format check (checks if data is entered in correct format / order)

Question 30

What is a check digit?

Answer 30

Error detection method where check digit is calculated from set of numbers, input with numbers, calculation performed on data again and check digit values compared to see if data entered is correct

Question 31

What is verification in computer science?

Answer 31

The process of checking that data is entered accurately, that it is the same as the original

Question 32

What are some examples of verification, and what happens in each?

Answer 32

Visual check - visually checking the entered data with the original side-by-side; double entry check - same data entered twice, usually by different people, and then entered data compared

Question 33

What is a trace table and its structure?

Answer 33

A structure which is completed when manually running an algorithm line by line, each column in a table for one variable and column for all outputs

Question 34

What can a trace table be used for?

Answer 34

Helps to follow a program to work out its purpose (see what changes made and when) and find and correct errors (shows what program actually does, different from what it should do, error found)

Question 35

What methods can computer programmers use to find errors?

Answer 35

Using a trace table, dry running by reading code, use featured within Integrated Development Environment (IDE)