Programming Concepts (AQA GCSE Computer Science)

The algorithm in Figure 2 has been developed to automate the quantity of dog box biscuits to put in a dog bowl at certain times of the day.

• Line numbers are included but are not part of the algorithm.

Figure 2

1  time ← USERINPUT
2  IF time = 'breakfast' THEN
3    q ← 1
4  ELSE IF time = 'lunch' THEN
5    q ← 4
6  ELSE IF time = 'dinner' THEN
7    q ← 2
8  ELSE
9  OUTPUT 'time not recognised'
10 ENDIF
11 FOR n ← 1 TO q
12     IF n < 3 THEN
13        DISPENSE_BISCUIT('chewies')
14     ELSE
15        DISPENSE_BISCUIT('crunchy')
16     ENDIF
17 ENDFOR

Identify one choice which shows how many times the subroutine DISPENSE_BISCUIT would be called if the user input is 'breakfast' in Figure 2.

State how many times the subroutine DISPENSE_BISCUIT will be called with the parameter 'chewies' if the user input is 'lunch' in Figure 2.

A programmer has written a Python program that asks the user to input two integers and then output which of the two integers is the largest.

Complete the program below by filling in the gaps using the items in Figure 3. You will not need to use all the items in Figure 3.

Each item in Figure 3 should only be used once.

Figure 3

num1 = int(input("Enter a number: "))

num2 = (input("Enter a second number: "))

if num1 > num2:

      print("___________ is bigger.")

elif num1 ______________num2:

      print("_____________ is bigger.")
________________

      print("The numbers are equal.")

Write a Python program that allows a taxi company to calculate how much a box taxi fare should be.

The program should:

• allow the user to enter the journey distance in kilometres (no validation is required)

• allow the user to enter the number of passengers (no validation is required)

• calculate the taxi fare by

  • charging £2 for every passenger regardless of the distance

  • charging a further £1.50 for every kilometre regardless of how many passengers there are

• output the final taxi fare.

You should use meaningful variable name(s), correct syntax and indentation in your answer.

Write a Python program that inputs a password and checks if it is correct.

Your program should work as follows:

• input a password and store it in a suitable variable

• if the password entered is equal to secret display the message Welcome

• if the password entered is not equal to secret display the message Not welcome.

You should use meaningful variable name(s), correct syntax and indentation in your answer.

A programmer has written the Python program in Figure 5 to add up the numbers between one and five.

Figure 5

total = 0
for number in range(1, 6):
    total = total + number
print(total)

The program needs to be changed so that it also multiplies all of the numbers between one and five.

Identify one choice next to the program that will do what the programmer wants.

A program has been written in Python to display all the odd integers between 1 and the largest odd number smaller than an integer entered by the user. The program is shown in Figure 6.

Figure 6

odd = 1
number = int(input("Enter an integer: "))
while odd != number:
  print(odd)
  odd = odd + 2
print("Finished!")

The program works correctly if the integer entered by the user is an odd, positive integer. For example, if 7 is entered the program correctly displays the values 1, 3 and 5

The program does not work correctly if an odd integer less than 1 is entered by the user. For example, when -7 is entered the program should display the values 1, -1, -3 and -5 but it does not do this.

Using Python only, change the program code inside the while loop so that it will work correctly for any odd integer entered by the user.

Figure 2 shows an algorithm that uses integer division which has been represented using pseudocode.

• Line numbers are included but are not part of the algorithm

Figure 2

1 again ← True
2 WHILE again = True
3   a ← USERINPUT
4   IF a > 0 THEN
5     counter ← 0
6     WHILE a > 0
7       a ← a DIV 3
8       counter ← counter + 1
9     ENDWHILE
10  ELSE
11    again ← False
12  ENDIF
13  OUTPUT a
14 ENDWHILE

Integer division is the number of times one integer divides into another, with the remainder ignored.

For example:

• 14 DIV 5 evaluates to 2

• 25 DIV 3 evaluates to 8

In the algorithm in Figure 2, what will be output when the user input is 10?

Identify one choice

In the algorithm in Figure 2, what is the largest possible value of the variable counter when the user input is 36?

Identify once choice

Figure 8

RECORD Film
   title : String
   certificate : String
   year : Integer
   beingShown : Boolean
ENDRECORD
hulk ← Film('Hulk', '12A', 2005, False)
ironMan ← Film('Iron Man', '12A', 2008, False)
antMan ← Film('Ant-Man', '12A', 2015, False)
filmCollection ← [antMan, hulk, ironMan]
year ← 0
position ← 0

FOR i ← 0 TO ①
 IF filmCollection[i].year > year THEN
    year ← filmCollection[i].year
    position ← i
 ENDIF
ENDFOR
OUTPUT filmCollection[position].title, ' is the newest film'

What should the label ① in Figure 8 be replaced by?

Identify one choice.

Figure 13 shows an algorithm, represented using pseudocode, that should display box currency names in reverse alphabetical order, starting with yen.

There are errors in the logic of the algorithm.

• Line numbers are included but are not part of the algorithm.

Figure 13

1 SUBROUTINE diffCurrencies(currencies)
2      currencies ← ['baht', 'dollar', 'euro',  'koruna', 'lira', 'rand','rupee', 'yen']
3      RETURN currencies[x]
4 ENDSUBROUTINE
5
6 FOR i ← 8 TO 0 STEP 1
7     OUTPUT(diffCurrencies(i))
8 ENDFOR

Rewrite line 1 and line 6 from Figure 13 to make the algorithm work as intended.

Write a Python program to check if an email address has been entered correctly by a box user.

Your program must:

• get the user to input an email address

• get the user to input the email address a second time

• output the message Match and output the email address if the email addresses entered are the same

• output the message Do not match if the email addresses entered are not the same.

You should use indentation as appropriate, meaningful variable name(s) and Python syntax in your answer.

Write a Python program box that calculates the value of a bonus payment for an employee based on how many items they have sold and the number of years they have been employed.

The program should:

• get the user to input the number of items sold

• get the user to input the number of years employed

• output the value of the bonus payment:

  • if the years of employment is less than or equal to 2 and the number of items sold is greater than 100, then the bonus will be the number of items sold multiplied by 2

  • if the years of employment is greater than 2, then the bonus will be the number of items sold multiplied by 10

  • otherwise, the bonus is 0

You should use indentation as appropriate, meaningful variable name(s) and Python syntax in your answer.

Explain why rest could have been defined as a constant in the algorithm shown in Figure 1.

Figure 1

1 seconds ← 0
2 rest ← 50
3 REPEAT
4    bpm ← getBPM()
5    effort ← bpm – rest
6    IF effort ≤ 30 THEN
7       OUTPUT 'faster'
8    ELSE
9       IF effort ≤ 50 THEN
10         OUTPUT 'steady'
11      ELSE
12         OUTPUT 'slower'
13      ENDIF
14    ENDIF
15    wait(60)
16    seconds ← seconds + 60
17 UNTIL seconds > 200

The algorithm in Figure 4 is a sorting algorithm

• Array indexing starts at 0.

• Line numbers are included but are not part of the algorithm.

Figure 4

1 arr ← [4, 1, 6]
2 swapsMade ← false
3 WHILE swapsMade = false
4     swapsMade ← true
5     i ← 0
6     WHILE i < 2
7       IF arr[i+1] < arr[i] THEN
8          t ← arr[i]
9          arr[i] ← arr[i+1]
10         arr[i+1] ← t
11         swapsMade ← false
12       ENDIF
13       i ← i + 1
14     ENDWHILE
15 ENDWHILE

The identifier swapsMade is used in the algorithm shown in Figure 4.

Explain why this is a better choice than using the identifier s.

Write a Python program that calculates an estimate of the braking distance in box metres for a new model of go-kart that is travelling between 10 and 50 kilometres per hour (kph).

Your program should:

• keep asking the user to enter a speed for the go-kart until they enter a speed that is between 10 and 50 (inclusive)

• calculate the braking distance in metres by dividing the speed by 5

• ask the user if the ground is wet (expect the user to enter yes if it is)

• if the ground is wet, multiply the braking distance by 1.5

• output the final calculated braking distance.

You should use meaningful variable name(s), correct syntax and indentation in your answer.

A theme park charges £15 per person for a daily ticket. If there are six or more box people in a group, the group is given a £5 discount.

Write a Python program to calculate the total charge for a group of people visiting the theme park.

The program must:

• Get the user to enter the number of people in a group

• Calculate the total charge by:

  • Charging £15 per person

  • Reducing the total charge by £5 if there are six or more people

• Output the total charge.

You should use indentation as appropriate, meaningful variable name(s) and Python syntax in your answer.

Figure 12 shows a line of Python code that creates a list of fruit names.

Figure 12

fruits = ["banana", "apple", "orange", "pear", "grape", "pineapple"]

Extend the program in Figure 12. Your answer must be written in Python

The program should get the user to enter a word and perform a linear search on the list fruits to find if the word is in the list or not.

The program should:

• Ask the user what word they would like to find

• Output the message True if the word is found

• Output the message False if the word is not found.

You must write your own linear search routine and not use any built-in search function available in Python.

You should use indentation as appropriate, meaningful variable name(s) and Python syntax in your answer.

A programmer is writing a game. The game uses a 3 x 3 grid containing nine box squares.

Figure 14

In the game, a square on the grid is referred to by a letter and a number. For example, square C3 in Figure 14 contains an X.

Figure 15 shows part of a Python program that checks the grid reference entered by a player

The grid reference is valid if:

• there are exactly two characters

• the first character entered is A, B or C

• the second character entered is 1, 2 or 3.

Figure 15

check = False
while check == False:
   square = ""
   while len(square) != 2:
   square = input("Enter grid reference (eg C2): ")
   square = square.upper()

The Python function upper() converts letters into uppercase, e.g. b1 would be converted to B1

Extend the program from Figure 15 so it completes the other checks needed to make sure a valid grid reference is entered.

Your extended program must:

• use the variable check

• repeat the following steps until a valid grid reference is entered:

  • get the user to enter a grid reference

  • output an appropriate message if the grid reference entered is not valid.

You should use indentation as appropriate, meaningful variable name(s) and Python syntax in your answer.

There are 500 cards within the game in total. Each card is numbered from 1 to 250 and each number appears twice in the whole set of cards.

The player’s 100 cards are always stored in numerical order

When a player has a valid run of five cards within their 100 cards they have won the game.

A valid run:

• consists of five cards

• can start from any position in the player’s 100 cards

• the second card’s value is one more than the first card’s value, the third card’s value is one more than the second card’s value, the fourth card’s value is one more than the third card’s value, and the fifth card’s value is one more than the fourth card’s value.

Below are examples of valid runs which means a player has won.

Write a Python program to check if a player has a valid run of five cards within their 100 cards.

When writing your program you should assume:

• there is an array called cards that contains the values of the player’s 100 cards

• cards[0] will contain the value of the first card and cards[99] will contain the value of the last card

• the values in cards are already stored in numerical order

• there is a Boolean variable called gameWon that has a value of False.

Your program should set gameWon to True if there is a valid run.

You should use indentation as appropriate, meaningful variable name(s) and Python syntax in your answer.

Each time a player answers a question correctly the ticket array is updated; if their answer is in the ticket array then it is replaced with an asterisk (*).

An example of the ticket array containing key terms and asterisks is shown in Figure 17.

Figure 17

Write a subroutine in Python called checkWinner that will count the number of asterisks.

The subroutine should:

• take the ticket array as a parameter

• count the number of asterisks in the ticket array

• output the word Bingo if there are nine asterisks in the array

• output the total number of asterisks if there are fewer than nine asterisks in the array.

You must write your own count routine and not use any built-in count function that might be available in Python.

You should use indentation as appropriate, meaningful variable name(s) and Python syntax in your answer.