1.1 Algorithms

Question 1

What does Unambiguous mean?

Answer 1

This means that the instructions cannot be misunderstood. Simply saying ‘turn’ would be ambiguous because you could turn left or right.
All instructions given to a computer must be unambiguous or it won’t know what to do.

Question 2

What does a Sequence mean?

Answer 2

An ordered set of instruction

Question 3

What does Algorithm mean?

Answer 3

A precise method for solving a problem

Question 4

What does High-level programming language mean?

Answer 4

A programming language that resemble natural human language

Question 5

What does Flowchart mean?

Answer 5

A graphical representation of an algorithm.
Each step in the algorithm is represented by a symbol.
Symbols are linked together with arrows showing the order in which steps are executed.

Question 6

What does Pseudo-code mean?

Answer 6

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

Question 7

What does Variable mean?

Answer 7

A container used to store data. The data stored in a variable is referred to as a value. The value stored in a variable is not fixed. The same variable can store different values during the course of a program and each time a program is run.

Question 8

What does identifier mean?

Answer 8

A unique name given to a variable or a constant. Using descriptive names for variables makes code much easier to read.

Question 9

What does Arithmetic operator mean?

Answer 9

An operator that performs a calculation on two numbers.

Question 10

What does Constant mean?

Answer 10

A container that holds a value that never changes. Like variables, constants have unique identifiers.

Question 11

What does IF…THEN…ELSE statement mean?

Answer 11

The IF…THEN…ELSE statement allows a choice to be made between 2 alternatives based on wether or not conditions is met.

Question 12

What does Relational operator mean?

Answer 12

An operator that compares 2 values

Question 13

What does Nested IF statement mean?

Answer 13

A Nested IF statement consists of one or more If statements placed inside each other. A Nested IF is used where there are more than 2 possible courses of action

Question 14

What does Indefinite iteration mean?

Answer 14

This is used when the number if iterations is not known before the loop is started. The iterations stop when a specified condition is met. This sort of loop is said to be condition controlled.

Question 15

What does Definite iteration mean?

Answer 15

This is used when the number of iterations, or turns of loops, is known in advance. It can be set to as many turns as you want. This sort of loop is said to be count controlled.

Question 16

What does Logical operator mean?

Answer 16

A Boolean operator using AND, OR and NOT.

Question 17

What does Random number mean?

Answer 17

A number within a given range of numbers that is generated in such a way that each number in the range has an equal chance of occurring. There are many devices for generating random numbers. A die is used in games to get a random number from 1 to 6. Computer programming languages have a function for generating random numbers across variable ranges. In the Edexcel pseudo-code there is a useful built-in RANDOM command.
RANDOM(upperLimit)
For example, number = RANDOM (6) would generate a random number from the numbers 1 to 6.

Question 18

What does Nested loop mean?

Answer 18

A loop that tuns inside another loop. The inner one executes all of its instructions for each turn of the outer loop.

Question 19

What does Concatenation mean?

Answer 19

The linking together of two or more items of information.

Question 20

What does Logic error mean?

Answer 20

An error in an algorithm that results in incorrect or unexpected behaviour.

Question 21

What does Trace table mean?

Answer 21

A technique used to identify any logic errors in algorithms. Each column represents a variable or output and each row a value of that variable.

Question 22

What does Simulation mean?

Answer 22

A representation of a real-world process or system

Question 23

What does Infinite loop mean?

Answer 23

A loop that is never-ending since the condition required to terminate the loop is never reached

Question 24

What does Array mean?

Answer 24

An organised collection of related values that share a single identifier.

Question 25

What does Ascending order mean?

Answer 25

This is arranging items from smallest to largest.

Question 26

What does Descending order mean?

Answer 26

This is arranging items from the largest to smallest.

Question 27

What does Traversal mean?

Answer 27

Travel across or through something. An array can be traversed by moving from the first to the last element in order to examine the data stored at each index position.

Question 28

What does Recursion mean?

Answer 28

A process that is repeated. For example, a document can be checked and edited, checked and edited and so on until its perfect.

Question 29

What does Brute force mean?

Answer 29

An algorithm design that does not include any techniques to improve performance, but instead relies on sheer computing power to try all possibilities until the solution to a problem is found

Question 30

What does Divide and conquer mean?

Answer 30

An algorithm design that works by dividing a problem into smaller and smaller sub-problems, until they are easy to solve. The solutions to these are then combined to give a solution to complete problem.

Question 31

What does Median mean?

Answer 31

The middle number when the numbers are put in ascending or descending order. If there are an even number if items in an ascending list, choose the item to the right of the middle.