Pseudocode Writing Practice

Unit 4 - Algorithms

Pseudocode Conventions Reference

Variables & I/O

  • variable = value
  • INPUT variable
  • OUTPUT message

Selection

  • IF condition THEN
  • ELSE IF condition THEN
  • ELSE
  • ENDIF

Iteration (Loops)

  • FOR i = start TO end
  • NEXT i
  • WHILE condition
  • ENDWHILE
  • REPEAT ... UNTIL

Operators

  • = (equal), <> (not equal)
  • <, >, <=, >=
  • AND, OR, NOT
  • MOD (remainder)

Question 1: Even or Odd (2 marks)

Write pseudocode that asks the user for a number and outputs whether it is "Even" or "Odd".
Hint: Use the MOD operator (number MOD 2 = 0 means even)

Question 2: Grade Calculator (3 marks)

Write pseudocode that asks for a test score (0-100) and outputs the grade:

  • - 80-100: "A"
  • - 60-79: "B"
  • - 40-59: "C"
  • - Below 40: "Fail"

Question 3: Countdown Timer (3 marks)

Write pseudocode that asks the user for a starting number, then counts down to 0, outputting each number. When it reaches 0, output "Blast off!".

Question 4: Average Calculator (4 marks)

Write pseudocode that asks the user to enter 5 numbers, calculates their average, and outputs the result.

Question 5: Password Validation (4 marks)

Write pseudocode for a login system that:

  • - Has a stored password of "secret123"
  • - Gives the user 3 attempts to enter the correct password
  • - Outputs "Access granted" if correct
  • - Outputs "Account locked" after 3 failed attempts

Question 6: Find Maximum (5 marks)

Write pseudocode that asks the user to enter numbers until they enter -1 (sentinel value). Then output the largest number that was entered.
Hint: Keep track of the maximum as you go

Challenge Question: Linear Search (6 marks)

Write pseudocode for a linear search algorithm that:

  • - Has an array called "names" with 5 names
  • - Asks the user for a name to search for
  • - Searches through the array to find the name
  • - Outputs the position if found, or "Name not found" if not
View Sample Solutions
Q1: Even or Odd 
INPUT number
IF number MOD 2 = 0 THEN
    OUTPUT "Even"
ELSE
    OUTPUT "Odd"
ENDIF
Q2: Grade Calculator 
INPUT score
IF score >= 80 THEN
    OUTPUT "A"
ELSE IF score >= 60 THEN
    OUTPUT "B"
ELSE IF score >= 40 THEN
    OUTPUT "C"
ELSE
    OUTPUT "Fail"
ENDIF
Q3: Countdown Timer 
INPUT start
count = start
WHILE count > 0
    OUTPUT count
    count = count - 1
ENDWHILE
OUTPUT "Blast off!"
Q4: Average Calculator 
total = 0
FOR i = 1 TO 5
    INPUT number
    total = total + number
NEXT i
average = total / 5
OUTPUT average
Q5: Password Validation 
password = "secret123"
attempts = 0
valid = FALSE
REPEAT
    INPUT guess
    attempts = attempts + 1
    IF guess = password THEN
        valid = TRUE
    ENDIF
UNTIL valid = TRUE OR attempts = 3
IF valid THEN
    OUTPUT "Access granted"
ELSE
    OUTPUT "Account locked"
ENDIF
Q6: Find Maximum 
INPUT number
max = number
WHILE number  -1
    IF number > max THEN
        max = number
    ENDIF
    INPUT number
ENDWHILE
OUTPUT max
Q7: Linear Search 
names = ["Alice", "Bob", "Charlie", "David", "Eve"]
INPUT searchName
found = FALSE
position = -1
FOR i = 0 TO 4
    IF names[i] = searchName THEN
        found = TRUE
        position = i
    ENDIF
NEXT i
IF found THEN
    OUTPUT "Found at position " + position
ELSE
    OUTPUT "Name not found"
ENDIF
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