Tutorial / Algorithms

Question 1

State characteristics of a good algorithm.

Question 2

What are the advantages of using pseudocode before implementing an algorithm in a programming language?

Question 3

Explain how a flowchart could help identify logic errors in an algorithm before testing it in code.

Question 4

How does the divide and conquer approach simplify the problem-solving process in software design? Provide a real-world example.

Question 5

What are the key differences between desk checking and using a trace table, and when might you use each?

Question 6

A Fibonacci series is a sequence of numbers where each is the sum of the two preceding numbers.

0, 1, 1, 2, 3, 5, 8, 13, 21, 34 and so on

Write an algorithm in which a user enters a number stored in the variable num. The algorithm prints all the numbers in the Fibonacci series less than or equal to the variable num.

Prepare your algorithm in pseudocode and test it with a trace table.

Question 7

Modify and test the algorithm you wrote in Question 6, in which a user is asked to enter the number of terms of the Fibonacci series to be printed.

Question 8

Deduce the purpose of the Python program given by using a trace table.

num1 = int(input("Enter the first number: "))
num2 = int(input("Enter the second number: "))

if num1 > num2:
    x = num1
else:
    x = num2

while True:  # Infinite loop until the break is hit
    if x % num1 == 0 and x % num2 == 0:
        print(x)
        break
    x = x + 1

Question 9

Deduce the purpose of the Python program given by using a trace table.

BEGIN
  total = 0
  FOR i = 1 TO 5
    IF i MOD 2 = 0 THEN
      total = total + i * 2
    ELSE
      total = total + i
    ENDIF
  NEXT i
  OUTPUT total
END

Question 10

Trace the algorithm below to identify why it does not work with the array alpha_part.

BEGIN
    alpha_part = [F, I, G, L, J, K, I, H]

    item = “J”
    lower_bound = 0
    upper_bound = LENGTH(alpha_part) - 1
    found = False

    WHILE found = False AND lower_bound <= upper_bound
        midpoint = (lower_bound + upper_bound) DIV 2
        
        IF alpha_part[midpoint] = item THEN
            found = True
        ELSEIF
            alpha_part[midpoint] < item THEN
            lower_bound = midpoint + 1
        ELSE
            upper_bound = midpoint - 1
        ENDIF
    ENDWHILE

    IF (found = True) THEN
        PRINT (“Item found at ”, midpoint)
    ELSE
        PRINT (“Item not present”)
    ENDIF
END