MockExam1

CS303E Mock Exam 1 Dr. Bill Young § Spring 2024 Name: EID: Read the questions carefully , and answer each question in the space provided. If you like, you can use scratch paper to do your work, but copy your answers neatly and legibly onto the test paper. Only answers recorded on the test paper will be graded. Don’t write in the spaces marked “Page Total” at the bottom of each page. Note: points as listed on the exam sum to 100, but your mock exam grade will be scaled to a 10-point scale. 1. (10 points: 1 point each) The following are true/false questions. Write either T or F in the boxes at the bottom of page 1. If there’s any counterexample, it’s false. (a) To run a Python file in batch mode, you will need to import the corresponding module from within the Python interpreter command loop. (b) 3rd is a valid variable name. (c) If x is a floating point number, then int(x) will return x rounded to the nearest integer. (d) The values 3 and "3" are equivalent representations of the number three, i.e. after the assignments x = 3 and y = "3" , x and y would hold exactly the same value. (e) Basic arithmetic operations on floats like addition, subtraction, multiplication, and division are only approximate in python, meaning that for certain calcu- lations the results may have some small error. (f) There is no way to include a backslash (i.e. this character → \ ) in a string, since the backslash is reserved for escape sequences. (g) If x is a variable holding a float, then the statement print(round(x, 2)) will display the value of x with exactly two digits after the decimal point. (h) The expression bool(None) is equivalent to False . (i) If you have an if-elif statement, then you must also have a corresponding else branch. (j) If a and b are booleans, the boolean expressions not (a and b) and not a and b may not evaluate to the same value. a b c d e f g h i j Page total: /10

CS303E Mock Exam 1 2 2. The following 10 questions (worth 1 point each) require you to evaluate a Python expression in the left hand column. For each question, write what the expression evaluates to on the provided line. If evaluation results in an error, write “error”; you don’t have to identity the specific type of error. You may assume the math library has been imported. You must show a value of the appropriate type. For example, 7.0 rather than 7 for a float and "7" instead of 7 for a string. Answers that do not indicate the data type correctly are wrong. (a) (ord(’z’) - ord(’y’)) * -4 + 2 (b) 0 // 8 + 4 (c) math.ceil(2.718) (d) "Hello" + "World" (e) round(3.14159, 3) (f) (3 % 100) and not (100 % 10) (g) "56" + "4" (h) int("2.5") (i) 60 / 3 + 4 * 2 (j) float(10) Page total: /10

CS303E Mock Exam 1 4 8. Which of the following is NOT an immutable type in python? A. int B. float C. str D. all of these are immutable 9. Suppose you want the following loop to print out 10 8 6 4 2 . for i in range(a, b, -2): print(i, end=" ") What values of a and b should you choose? A. a = 12 and b = 2 B. a = 10 and b = 2 C. a = 12 and b = 0 D. a = 10 and b = 0 10. Assume that a is an integer. Three of the following boolean expressions are equiv- alent regardless of the value of a . Which one is not equivalent to the others? A. (a < 10) or (a > 50) B. not (10 < a < 50) C. (50 < a) or (10 > a) D. not ((a <= 50) and (10 <= a)) 11. Which of the following operators has the highest precedence? A. + (addition) B. * (multiplication) C. ** (exponentiation) D. % (mod) 12. Which of the following is NOT an advantage of using functions? A. Functions allow for streamlined reuse of code. B. It’s easier to read and maintain code that’s divided logically into functions. C. Dividing a program into functions allows the python interpreter to execute the code more quickly. D. Functions provide an abstract interface for some behavior without requiring the caller to know the implementation details. 3 4 5 6 7 8 9 10 11 12 Page total: /20

CS303E Mock Exam 1 5 Questions 13–20 require you to trace the behavior of some Python code and identify the output of that code. For each question, write the output for the code segment in the provided box. If executing the code gives an error, write “ERROR” in the box; you’re not required to identify what type of error occurs. Don’t worry about whether it goes to the next line at the end. 13. (3 points) print("Greetings", "I have" + "come from", "a different", \ "planet", sep="$", end="!!!") 14. (3 points) def a(s, x): return s + ("!" if (x > 0) else "?") val = "hello" print(val, end=" ") a(val, 2) print(val) 15. (3 points) # a similar type of bowling handicap max = 300 multiplier = 0.5 average = 240 handicap = int((max - average) * multiplier) handicap = max(handicap, 0) print(handicap) Page total: /9

CS303E Mock Exam 1 7 19. (3 points) x = 36 for d in range(1, x + 1): if x % d == 0: print(d, end=" ") 20. (3 points) def f(a=4, b=3, c=5, d=1): return a+b*c+d print(f(5, 2)) Page total: /6

CS303E Mock Exam 1 8 21. (10 points: 1 point each) The following questions require you to write a Python expression that returns the indicated value. You can assume that any modules you need have been imported. Note that this asks for a single, one-line expression for each question, not a longer program fragment. So, you should not have any assignments, loops, or if statements. (a) the result of a standard die roll (i.e. a uniformly random integer between 1 and 6, inclusive) (b) for a given integer n , a boolean indicating whether n is divisible by 3 but not 5 (c) for a given integer n having at least two digits, the digit in the tens place in n , i.e. the second digit from the right (d) for given floats a , b , and c , the average of these three values (e) for given floats a , b , and c , the range of these three values, i.e. the difference between the largest and smallest value (f) for given integers x and y , the remainder when x is divided by y (g) a user-provided input, converted to a floating-point value, after prompting the user with "Enter a number" (h) for a given lowercase letter of the alphabet ch between ’a’ and ’y’, the letter that comes after it in the alphabet (also lowercase) (i) for a given float num , num as a string, displayed to three decimal places (j) for a given float num , the smallest integer at least as big as num Page total: /10

CS303E Mock Exam 1 10 23. (10 points) You’re playing a video game similar to a particular Nintendo property which will not be named. In this game there are three different things you can encounter in a level: a small coin box which gives you 20 coins, a large coin box which gives you 50 coins, and a goomba which steals all the coins you have. You start with 0 coins, and each time your coin count gets to 100 or more, you immediately lose 100 coins and gain an extra life. Given a sequence of things you encounter in a level, you’d like to know how many extra lives you’ll gain and how many coins you’ll end up with. For example, suppose the sequence is large box, large box, small box, goomba, small box, large box, large box, small box, large box, goomba, goomba, end. You’ll first gain 50 coins, then 50 more (total of 100, so you gain a life and now have 0 coins), then 20 more (total of 20), then lose all 20 coins (total of 0), then gain 20 coins (total of 20), then 50 more (total of 70), then 50 more (total of 120, so you gain another life and now have 20 coins), then 20 more (total of 40), then 50 more (total of 90), then lose all 90 coins (total of 0), then lose all 0 coins (total of 0), and then the level is over. In total you gained 2 extra lives and ended with 0 coins. Complete the extraLives function that reads in a sequence of things you encounter in a level, provided one-per-line as user input. Each line will have either ”small box”, ”large box”, or ”goomba”, except for the last which will have the word ”end”. The function should determine and print how many extra lives you gain and how many coins you end the level with. See the example calls for how this should be formatted. Here is an example call to the function, assuming the input sequence is large box, large box, small box, goomba, small box, large box, large box, small box, large box, goomba, goomba, end, as in the explained example: >>> extraLives() extra lives: 2 coins: 0 Here is another example call to the function, assuming the input sequence is small box, large box, small box, goomba, small box, large box, large box, goomba, small box, large box, end: >>> extraLives() extra lives: 1 coins: 70

CS303E Mock Exam 1 11 def extraLives(): Page total: /10