Component 2 Flashcards Textbook Flashcards by Hayden Lo

What is an algorithm?

A series of instructions that solves a problem in a finite number of steps

How well did you know this?

Not at all

Perfectly

What three criteria lead to a successful algorithm?

Accuracy
Consistency
Efficiency

How well did you know this?

Not at all

Perfectly

What does unambiguous mean?

Written in a way that makes it completely clear what is meant

How well did you know this?

Not at all

Perfectly

What are the two ways to plan and design an algorithm?

Visual (Using flow chart symbols)
Text (Using a written sequence of instructions)

How well did you know this?

Not at all

Perfectly

What is the difference between an algorithm and a problem?

Before you can write a program to solve a problem, you have to work out the algorithm first

How well did you know this?

Not at all

Perfectly

What is a variable?

A storage location used to store a value; this could be text or a number. The value stored in the variable may change as the program is run.

How well did you know this?

Not at all

Perfectly

What are the rules for a variable name?

Must be written before a value is assigned to it
Cannot start with a number
Must not have spaces
Must make sense in algorithm

How well did you know this?

Not at all

Perfectly

What is ‘=’ in OCR pseudocode?

Assignment of a value to a variable

How well did you know this?

Not at all

Perfectly

What is ‘==’ in OCR pseudocode?

Shows equality

How well did you know this?

Not at all

Perfectly

What is the flow chart symbol for a terminator and what does it show?

Oval / Rounded Rectangle
Start or end of algorithm

How well did you know this?

Not at all

Perfectly

What is the flow chart symbol for a process and what does it show?

Rectangle
Process in algorithm e.g. Calculating price

How well did you know this?

Not at all

Perfectly

What is the flow chart symbol for a decision and what does it show?

Diamond
Have one of two answers; yes or no, true or false

How well did you know this?

Not at all

Perfectly

What is the flow chart symbol for an input or output and what does it show?

Parallelogram
Shows data into algorithm or outputs from it

How well did you know this?

Not at all

Perfectly

What does an arrow show in a flow chart?

Sequence of steps in the algorithm
Usually vertical or horizontal

How well did you know this?

Not at all

Perfectly

What is a flow chart?

Visual representation of the sequence of steps in an algorithm

How well did you know this?

Not at all

Perfectly

What is assignment?

Giving a variable or constant a value by linking a value to the identifier

How well did you know this?

Not at all

Perfectly

What is an identifier?

A unique name given to a variable or constant in your algorithm which makes your algorithm easier to read and understand

How well did you know this?

Not at all

Perfectly

What is pseudocode?

A structured, code-like language that can be used to describe an algorithm

How well did you know this?

Not at all

Perfectly

What are keywords?

Used in pseudocode for common operators; written in capital letters

How well did you know this?

Not at all

Perfectly

What are some example keywords?

INPUT- Getting values into the algorithm from user via keyboard
OUTPUT- Messages or results displayed on screen

How well did you know this?

Not at all

Perfectly

What are the pseudocode arithmetic operators for addition, subtraction, multiplication and division?

+ , - , * , /

How well did you know this?

Not at all

Perfectly

What are the pseudocode arithmetic operators for integer division and modulus?

DIV (only evaluates quotient which is the integer)
MOD (only evaluates remainder)

How well did you know this?

Not at all

Perfectly

List all the comparison operators (and what they evaluate to)

< - Less than (True)
> - Greater than (False)
== - Same as (True)
!= - Not equal to (True)
<= - Less than or equal to (True True)
>= - Greater than or equal to (True False)

How well did you know this?

Not at all

Perfectly

True or False: Arithmetic Operators are evaluated AFTER comparison operators

False, evaluated BEFORE.

How well did you know this?

Not at all

Perfectly

What are the three Boolean operators?

AND - Checks both conditions are true or false OR - Checks EITHER conditions is true NOT - Reverses Boolean Value (e.g x>y = False, NOT reverses evaluation to True)

What is an operator?

Symbol that shows an operation

What are the three basic programming constructs ?

- Sequence - Selection - Iteration

What is an exponentiation?

Base integer is raised to power of exponent integer, Operator is ^

What are the two types of iteration?

- Condition- controlled loop - Count-controlled loop

What is nesting?

Combining code together, putting a while loop inside a while loop

What is an array?

Data structure that allows storage of multiple items in a single variable

What is a subprogram?

Clear, independent blocks of code within a computer program which can be called and accessed by main program

What is 'call'?

Starting the subprogram

What are subprograms which return values known as?

Functions

What are subprograms which don't return values known as?

Procedures

What is decomposition?

Breaking problem down into smaller sub-problems until these tasks are solved

What is a string?

A sequence of characters surrounded by quotation marks

What is concatenation?

Merging or joining two strings together using a concatenation operator (+)

What is abstraction?

Process of removing unnecessary details from a problem

What is time efficiency?

The number of steps to complete the algorithm

What is space efficiency?

The amount of memory required to complete the algorithm

What is brute force?

Process that tries all possible alternatives to find a solution

What is an input?

Data that a program receives and processes

What sources can inputs come from?

- User Input - Files - Sensors - Networks

What is an output?

Results of a program's processing

How can an output be presented?

- On Screen - Printed Out - Sent to other devices or programs

How do you make use of data retrieved by an input function?

- Assign a return value to a variable which allows program to store and manipulate input data

What is a sequence?

Executing a series of statements in a specific order, following linear flow

What is selection?

Enables program to make decisions based on conditions

What is iteration?

Allows a set of instructions to be repeated multiple times as long as certain condition is true

What happens when sequence fails and instructions are executed in wrong order?

- Program's behavior can deviate from intended logic causing logic errors, unexpected results or crashes

What are the two types of iteration?

Count-controlled Condition-controlled

What is count-controlled iteration?

Number of times the loop is executed is predetermined before the loop starts

What is condition-controlled iteration?

Loop continues until a certain condition is met

What are the arithmetic operators and what do they do?

+ - Addition - - Subtraction * - Multiplication / - Division ^ - Exponentiation (raises to the power) DIV - Quotient (returns integer) % - Modulus (also MOD, returns remainder)

What are the comparison operators and what do they do?

== - equal to != - not equal to < - less than <= - less than or equal to > - greater than >= - greater than or equal to

What are the Boolean operators and what do they do?

AND - Returns true if both operand are true OR - Returns true if either operands are true NOT - Reverses logic state of its operand

What are the 5 common data types?

Integer - Whole Numbers Float - Decimal Numbers Boolean - True/False Values Character - Single alphanumeric character String - Sequence of characters

What is string concatenation?

Process of joining two strings together using the '+' operator

How can you convert other variables into string for string concatenation?

Create a new string variable and assign it to to_string(variable_name)

How to use substrings?

Use the variable.substr(num1, num2) in which num1 is the index you should start at, including 0, and num2 is the number of characters to include afterwards