Midterm Exam 1

Exam Format and Rules

• The exam is in class, Wednesday, February 26.
• A mix of multiple choice, fill-in-the-blank, and long answer questions.
• You will not be programming in PyCharm, but you may be asked to write or edit code snippets by hand.
• You may use your own hand-written notes and scrap paper. No other resources are permitted.
• Honor Code violations on the any exam result in a course grade of F.
• Failure to submit an exam results in a course grade of F.

Content

• Study key terms from slides and labs. Look for boldfaced, underlined terms in slides and emphasized terms in labs.
• Study Knowledge Checks from labs.
• Describing Operating Systems concepts (week 1).
• Linux CLI commands (week 3)
• Describing the phases of the Software Lifecycle (week 3).
• Debugging concepts and basic debugger controls (week 4).
• Writing a good Problem Statement when provided a high-level description of the program goals. (week 4)
• Testing concepts (terms) and application (weeks 5-6), including:
  • Creating a control flow graph for a given function.
  • Writing or analyzing unit tests for a given function, including:
    • assert statements
    • computing line coverage by hand
    • testing if exceptions are raised using pytest functions

Sample CFG and Testing problems

You will be asked to draw CFGs and write test cases that cover all program paths.

Disclaimer: You will have other knowledge check questions beyond these types of questions.

Sample 1

1
2
3
4
5
6
7

def is_prime(number):
    if number < 2:
        return False
    for i in range(2, int(number ** 0.5) + 1):
        if number % i == 0:
            return False
    return True

1. Draw the CFG for this code using the conventions from class.
2. List the unique program paths.
3. Add assert statements to the following test case that exercise all unique program paths.

   def test_is_prime():
      # Your code here.
   

Solution

CFG for is_prime()

def test_is_prime():
   # Some paths can be exercised with multiple input values. 
   # The goal is to exercise all program paths.

   assert is_prime(1) == True  # tests path (1, 2, 3)
   assert is_prime(2) == True  # path (1, 2, 4, 7)
   assert is_prime(4) == False  # path (1, 2, 4, 5, 6)
   assert is_prime(5) == True  # path (1, 2, 4, 5, 4, 7)

Sample 2

14
15
16
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18
19
20
21
22
23
24
25
26
27
28
29

def generate_fibonacci(n):
    if n <= 0:
        return "Error: Number of terms must be a positive integer"
    
    fibonacci_sequence = [1]
    a = 1
    b = 2
    count = 1
    
    while count < n:
        fibonacci_sequence.append(a)
        # Update values of a and b to the next numbers in the sequence
        a, b = b, a + b
        count += 1

    return fibonacci_sequence

1. Draw the CFG for this code using the conventions from class.
2. List the unique program paths.
3. Add assert statements to the following test case that exercise all unique program paths.

   def test_generate_fibonacci():
      # Your code here.
   

Solution

CFG for generate_fibonacci()

def test_generate_fibonnaci():
   # Some paths can be exercised with multiple input values. 
   # The goal is to exercise all program paths.

   assert generate_fibonnaci(0) == "Error: Number of terms must be a positive integer"  # tests path (14, 15, 16)
   assert generate_fibonnaci(1) == [1]  # path (14, 15, 18-21, 23, 29)
   assert generate_fibonnaci(6) == [1, 1, 2, 3, 5, 8]  # path (14, 15, 18-21, 23, 24-27, 23, 29)

Sample 3

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def factorial(n):
    # Input validation
    if not isinstance(n, int) or n < 0:
        return "Error: Input must be a non-negative integer"
    
    # Use iterative approach
    result = 1
    for i in range(1, n + 1):
        result *= i
    return result

1. Draw the CFG for this code using the conventions from class.
2. List the unique program paths.
3. Add assert statements to the following test case that exercise all unique program paths.

   def test_factorial():
      # Your code here.
   

Solution

CFG for factorial()

def test_factorial():
   # Some paths can be exercised with multiple input values. 
   # The goal is to exercise all program paths.

   assert factorial("Alice") == "Error: Number of terms must be a positive integer"  # tests path(36, 38, 39)
   assert factorial(-1) == "Error: Number of terms must be a positive integer"  # also tests path(36, 38, 39)
   assert factorial(0) == 1  # tests path(36, 38, 42, 43, 45)
   assert factorial(5) == 120  # tests path(36, 38, 42, 43, 44, 43, 45)