CMU 15-112: Fundamentals of Programming and Computer Science
Quiz 3 (35 minutes)

Quiz 3 frontmatter:

(This quiz was given in the CS Academy quiz proctoring app on 7/26)

• You may do the questions in any order, and you may leave them incomplete and return to them later if you wish. HOWEVER, if you begin a free response question (where you can run python code) any viewed but unsubmitted CTs and multiple choice questions will automatically be submitted and locked (so that you cannot run the CT code in the free response editor).
• You have a fixed time to answer all the questions.
  • Watch the timer carefully!
• If you are locked out due to a security error, exit the breakout room to speak with the TA or faculty member on duty

Quick Reminders:

• Plug in your phone and computer
• Turn on do-not-disturb on your phone and computer and make sure your phone won't go to sleep or remove you from the zoom call or turn off your camera.
• Your phone must be properly positioned as described below
• Other than your main monitor and your phone, you must not have any other computer monitors on, and no other phones/tablets/calculators/notes/other resources should be accessible.
• Follow all proctoring instructions exactly. Failure to adhere to proctoring policy may result in a zero on the quiz, and possibly a deduction from your semester grade based on severity.
• Any attempt to subvert, exploit, or misuse the testing environment (including attempts to access the raw content or investigate the underlying source code) will be considered a severe academic integrity violation, possibly leading to course failure or other significant penalties.

During the quiz

1. You may not ask questions during the quiz.
   • If you are unsure how to interpret a problem, take your best guess.
2. You may not leave the quiz and return, and you may not interact with anyone else (remotely or in person) except for the TAs or faculty until the quiz is submitted.
3. You must not leave the full-screen testing environment at any time. If anything except the testing environment is visible on your screen, it will trigger a security error, and you will be locked out of your quiz / you may receive a deduction or a zero. Additionally, we will investigate whether this could be a matter of academic integrity.
4. All of these must be visible to your phone's camera at all times:
   • All of your screen, and any other screens nearby
   • Most of your desk
   • Your mouse and keyboard
   • Note: You must not block your screen with your head/arms/etc while taking the quiz
   • You must not have any other computer monitors on, and no other phones/tablets/calculators/notes/other resources should be accessible.
5. If you are locked out due to a security error, exit the breakout room immediately to speak with the TA or faculty member on duty. At their discretion, they may unlock the quiz and allow you to continue.
6. When you finish a question, press the submit button to lock in your answer. You will not be able to return and change your answers after pressing submit. Once the allotted time elapses, the quiz will auto-submit with your current progress. See above for more details

You must use your phone to join the proctored Zoom meeting. If you cannot join Zoom on your phone:

• You may receive a deduction if this is due to a lack of preparedness
• Join Zoom on your computer instead.
• You MUST still position your phone to see the items listed above, and you MUST record a video of the entire quiz until your proctor releases you.
• We will not grade any section of the quiz that we did not receive full video for, and you may receive a zero.This is true even if your phone runs out of storage space.
• After the quiz, immediately upload this to Google Drive or Box or Dropbox and then send us a link.You must use one of these three services. If you email the video directly or upload it to another source, you will receive a zero.
• If we cannot access or view your video, or if you do not record one, we will give you a zero, so make sure your upload is successful. We must be able to view the video soon after the quiz, so please begin uploading immediately.
• When your upload is complete, fill out the tech fail form and copy in the link to your video. Do not send it by email unless we request it.

After the quiz

1. If you submit your quiz before time is up, wait until everyone else finishes and your proctor gives you further instructions.
2. Wait until your proctor dismisses you, and then please exit Zoom. You are done! Rejoin the lecture Zoom session on your laptop.

For any tech fails (laptop or internet stops working, etc.):

• If you are still in Zoom, exit the breakout room and speak with the TA/Faculty in the main room. Do not speak while in the breakout room.
• If you cannot immediately speak with a TA or professor, stop taking the quiz and fill out the tech fail form linked from the course website's forms?page. (Note: A security error is not a tech fail, unless you are unable to return to the testing environment without triggering another one. We may be able to address accidental security errors in certain circumstances, but only if they are immediately brought to our attention.)
• We will email you soon to resolve the issue.

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1. True/False [3 points]

Write only the whole word "True" or "False" (and not just T or F).

The make_dataclass function returns a generic object, whereas SimpleNamespace returns a new class.

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2. True/False [3 points]

Write only the whole word "True" or "False" (and not just T or F).

An object is an instance of a class, and can have properties and methods.

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3. True/False [3 points]

Write only the whole word "True" or "False" (and not just T or F).

At the end of the following code, A and B are no longer aliases of the same list:

A = [1, 2, 3]
B = A
B = B + []

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4. True/False [3 points]

Write only the whole word "True" or "False" (and not just T or F).

Destructive functions and methods must not return any value other than None.

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5. True/False [3 points]

Write only the whole word "True" or "False" (and not just T or F).

Tuples are very similar to lists, except tuples cannot be destructively modified.

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6. Code Tracing [15 points]

What does the following code print?

#Hint: Draw a box and arrow diagram!
import copy
def ct1(a):
    b = a
    c = copy.copy(a)
    b[0] = 42
    a.append("wow")
    c[3] = 2 * c[3]
    b = b[:2] + ["hi"] + b[2:]
    c.remove(1)
    a[-2] = 112
    print("a:", a)
    print("b:", b)
    print("c:", c)
z = ["jul", "26", 1, 100]
ct1(z)
print("z:", z)

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7. Reasoning over Code [10 points]

Find an argument for L that makes rc1(L) return True. Write your answer below.

def rc1(L):
    if (not isinstance(L, list)):
        return False
    A = []
    B = []
    while(L != []):
        A.extend([L.pop()])
        B = [L.pop(0)] + B
    return A + B == list(range(2, 6))

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8. Free Response 1: dataCleaner(L) [25 points]

Write the function dataCleaner(L) which takes a list of strings like ['aBc+123', 'Hey 3P0', 'R2-D2!'] and non-destructively returns a new list of strings where:

• All non-letter non-numeric characters have been removed (including spaces, punctuation, and possibly escape characters)
• All letters are lowercase

The list and its strings should otherwise be the same.

So, dataCleaner(['aBc+123', 'Hey 3P0', 'R2-D2!']) should return ['abc123', 'hey3p0', 'r2d2']
Look at the test cases for more examples! And remember to be non-destructive!
Hint: It is a *bad* idea to try converting the list to a string and splitting it up again later.
Hint: Use helper functions to make this easier to debug!

import copy

def dataCleaner(L):
    return 42

def testDataCleaner():
    print('Testing dataCleaner()...', end='')
    assert(dataCleaner(['aBc+123?']) == ['abc123'])
    assert(dataCleaner(['aBc+123', 'Hey 3P0', 'R2-D2!']) == ['abc123', 'hey3p0', 'r2d2'])
    assert(dataCleaner(['1 ', 'Hungry-', '?Axolotl??']) == ['1', 'hungry', 'axolotl'])
    assert(dataCleaner([" '\t\n'  ", '12"3"45', '(-,@#$%^)' , 'NICE']) == ['', '12345', '', 'nice'])
    assert(dataCleaner([]) == [])

    #Test for non-destructiveness
    L = ['aBc+123', 'Hey 3P0', 'R2-D2!']
    L2 = copy.copy(L)
    assert(dataCleaner(L) == ['abc123', 'hey3p0', 'r2d2'])
    assert(L == L2)

    #Remember, we may use more test cases! 
    #Don't hard-code or assume certain characters won't be used! 
    print('Passed.')


testDataCleaner()

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9. Free Response: Clicky Grid Animation [35 points]

Write an animation with the following properties:

1. A canvas contains a 9x9 grid with a 10-pixel margin.
   1. The grid should scale with the canvas, but assume the canvas is at least 400x400
   2. All cells are initially red with a black border.
2. When a user clicks a red cell, that cell turns blue.
   1. Up to 5 cells can be blue at any time. Once a 6th cell turns blue, the oldest blue cell (the one that has been blue longest) becomes red again. (Hint: Remember Snake!)
   2. Clicking on a blue cell does nothing at all
3. Every 5 seconds, the oldest blue cell turns red.
   1. Note: The timer should *not* reset when a new cell turns blue with a mouse press, even if the new cell results in an old cell becoming red.

Hint 1: Remember Snake!
Hint 2: Write getCell and getCellBounds!

As before, you can't run animation code, but we will grade with this in mind. As always, we give partial credit, even if you leave out a feature. (For example, you can still get partial credit if you leave getCellBounds or getCell blank, or if you don't use a margin, or if you don't remove the oldest blue cell, etc)

######Helpers#########
def almostEqual(d1, d2, epsilon=10**-7): #helper-fn
    return (abs(d2 - d1) < epsilon)

#(This works the same as the one you've seen before)
def roundHalfUp(d): #helper-fn
    sign = 1 if (d >= 0) else -1
    d = abs(d)
    n = int(d)
    if (d - n >= 0.5): n += 1
    return sign * n
######################

from cmu_112_graphics import *

def appStarted(app):
  pass

def mousePressed(app, event):
  pass

def timerFired(app):
  pass

def getCellBounds(app, row, col):
  return (x0, y0, x1, y1)

def getCell(app, x, y):
  return (row, col)

def redrawAll(app, canvas):
  pass

runApp(width=400, height=400)

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