Computer Science for IGCSE & O level - Algorithm Design And Problem Solving (Section 11)
1
Which of the following is NOT a common method of verification?
Απάντηση
(C)
Type check
2
What is the purpose of the outermost `FOR` loop in the bubble sort example (i.e., `FOR Index <- 1 TO Length - 1`)?
Απάντηση
(B)
To control the number of passes through the list.
3
To test a program for a salary range, from a minimum to a maximum, which data type is most relevant?
Απάντηση
(D)
Extreme data
4
When testing a program that calculates an employee's pay, which type of test data should you employ to verify the correct handling of the minimum (e.g., 0 hours worked) and maximum possible hours worked?
Απάντηση
(D)
Extreme data
5
In the context of algorithm design, what does the term "verification" primarily refer to?
Απάντηση
(C)
Checking that data has been accurately copied from one source to another.
6
Which validation techniques involve a human user checking the data?
Απάντηση
B
C
7
In a typical `FOR...TO...NEXT` loop, what happens after the `NEXT` statement is executed?
Απάντηση
(B)
The loop variable is incremented, and the loop starts again.
8
In pseudocode, what do you use to assign a value to an item/variable?
Απάντηση
(C)
The <- sign
9
To test the boundaries of a program, what data is used?
Απάντηση
(C)
Boundary data
10
What are the essential components of data validation techniques?
Απάντηση
A
B
C
11
Which of the following is a type of validation check?
Απάντηση
(D)
Character check.
12
When sorting data using a bubble sort, the data is typically sorted in which order?
Απάντηση
(B)
Ascending or descending order.
13
What does the 'searching using a linear search' standard method of solution involve?
Απάντηση
(A)
Comparing each item in a list against a target value until it is found or the end of the list is reached.
14
Which of the following is generally a step in the algorithm design process?
Απάντηση
A
B
D
15
What does the algorithm 'totaling' usually aim to achieve?
Απάντηση
(B)
Calculating the sum of a set of values.
16
When should a WHILE...DO...ENDWHILE loop be used?
Απάντηση
(B)
When the number of iterations is not known and the action must be repeated until a certain condition is met.
17
What is the purpose of the design stage in software development?
Απάντηση
(C)
To plan the program's structure and components.
18
What are the different types of checks that a program might include for validation?
Απάντηση
A
B
D
19
What aspect of an algorithm is most effectively illustrated through the use of a trace table?
Απάντηση
(C)
The step-by-step execution flow and how variables change.
20
Which types of data are used to determine if a program works correctly?
Απάντηση
A
B
C
D
21
Check digits mainly help with...
Απάντηση
(B)
Spotting data entry mistakes.
22
In the bubble sort example, what would the `Temperature[Index] <= Temperature[Index + 1]` represent?
Απάντηση
A
D
23
Which checks are examples of the verification process?
Απάντηση
B
C
24
What is the purpose of a 'bubble sort' algorithm?
Απάντηση
(B)
To sort a list of items.
25
What is the role of flowlines in a flowchart?
Απάντηση
(B)
To specify the sequence of steps in the algorithm.
26
In the `CASE OF` structure, how are the different code blocks selected for execution?
Απάντηση
(C)
Based on the value of an expression.
27
What does the 'storage' component of a computer system refer to?
Απάντηση
(C)
The data that needs to be stored for future use.
28
What kind of input does the algorithm for validating the percentage mark use?
Απάντηση
(B)
An integer.
29
In the context of the alarm clock algorithm, what is the expected behavior of the code within the WHILE loop?
Απάντηση
(B)
To repeatedly monitor the time until the condition is met.
30
What is the primary purpose of a structure diagram when designing an algorithm?
Απάντηση
(D)
To provide a high-level overview of the algorithm's components and their relationships.
31
What is a key characteristic of an 'algorithm'?
Απάντηση
A
B
C
32
What is the role of a presence check in data validation?
Απάντηση
(A)
To ensure data is entered into a field.
33
Which of the following is a valid use of the CASE structure?
Απάντηση
(B)
To display different messages based on a user's input.
34
What is the role of a structure diagram?
Απάντηση
(B)
To visualise and document the structure of the software.
35
In the context of algorithms, what are the typical components of a loop structure?
Απάντηση
A
B
C
D
36
When using a linear search to find an item in an unsorted list, what is the worst-case scenario?
Απάντηση
(B)
The item is not in the list.
37
In algorithm design, what is the significance of the step that involves ‘constructing your algorithm’?
Απάντηση
(C)
To ensure that the algorithm functions correctly and that it will execute.
38
What is the purpose of an algorithm?
Απάντηση
(B)
To solve a specific problem.
39
What is the role of a CASE OF statement?
Απάντηση
(A)
To choose between many values
40
In the context of data validation, what is a screen/visual check primarily used for?
Απάντηση
(C)
To allow the user to visually confirm the data they've entered is correct.
41
Why is boundary data used in the testing phase?
Απάντηση
(A)
To test the extreme limits of data input.
42
Which of the following is *not* a common type of validation check?
Απάντηση
(D)
Efficiency check
43
Testing an algorithm's performance with expected inputs uses...
Απάντηση
(A)
Normal data.
44
What is the purpose of using comments within an algorithm or its code?
Απάντηση
(C)
To explain the code to someone else or to yourself later.
45
What is the purpose of using flow lines within a flowchart?
Απάντηση
(B)
To denote the flow of execution.
46
Which of the following actions is most crucial for creating reliable algorithms?
Απάντηση
(C)
Thorough testing with a range of inputs.
47
What is the function of the 'ELSE' clause in an `IF...THEN...ELSE` structure?
Απάντηση
(C)
To define the actions to be taken when the condition is false.
48
Which type of check verifies that the data entered is a number?
Απάντηση
(C)
Type Check
49
Which type of check ensures the data entered is of the correct type?
Απάντηση
(B)
Type Check
50
What is the function of an algorithm in the context of computing?
Απάντηση
(C)
To provide a set of instructions for solving a specific problem.
