Homework 1

Due: Tuesday, February 4 at 11:59 pm

Instructions

Please read the instructions carefully. An incorrectly formatted submission may not be counted.

There are three questions in this assignment. For each question, put your answer in a plain text python file (.py) named q1.py, q2.py and q3.py. If the question involves pseudocode, put your pseudocode in a line starting with # as we did in class so that Python ignores it. Include any test cases to ensure your code works, as we did in the in-class examples. Put q1.py, q2.py, and q3.py in a folder called uni-hw1 (so for me this would be tkp2108-hw1). Then compress this folder into a .zip file. For most operating systems, you should be able to right click and have a “compress” option in the context menu. This should create a file called tkp2108-hw1.zip (with your uni). Submit this on courseworks.

Part 1

Write pseudocode for your morning routine during a Columbia semester. Aim for 10–20 steps. Here’s mine:


# 1.  If day is Monday or day is Wednesday or day is Friday:
# 2.      If weather is nice:
# 3.          Setup bicycle                                    --- This is probably a subroutine!
# 4.          Bike to Hudson Yards
# 5.      Else:
# 6.          Grab umbrella
# 7.          Head to 72nd street 2-3 train
# 8.  Else if day is Saturday or day is Sunday:
# 9.      Sleep in
# 10.     Watch soccer
# 11. Else:
# 12.     Make coffee                                           --- This is probably a subroutine!
# 13.     If weather is nice:
# 14.          Setup bicycle                                    --- This is probably a subroutine!
# 15.          Bike to Columbia
# 16.      Else:
# 17.          Grab umbrella
# 18.          Head to 79th street 1 train

Part 2

In many sports, winning by a single point is not allowed. Instead, you must win by two. For example in Tennis:

Both players start at 0–0
As players score points, their score goes 0–15–30–40 (for this problem, lets call it 0–1–2–3)
The first player to 4 wins, but players must win by 2

So if both players have 3 points (40–40), the next point does not win. Instead, a player must score two consecutive points in order to win by two.

First, let’s write pseudocode for an algorithm that determins the winner. Let P1 be player one’s score, let P2 be player two’s score. Return 1 if player one wins, return 2 if player two wins, otherwise return 0. Feel free to use number of points (e.g. 0,1,2,3) instead of Tennis’s 0–15–30–40. Here is some starter pseudocode, feel free to modify:


# 1. Let P1 be player one's score
# 2. Let P2 be player two's score
# 3. If P1 < 4 and P2 < 4, return 0
# ...

Next, turn this pseudocode into Python code. Here are a few example test cases you might find helpful:


print(tennisWinner(0, 0))   # prints "0", since no winner 
print(tennisWinner(4, 0))   # prints "1", since player 1 won
print(tennisWinner(4, 3))   # prints "0", since player 1 has not won by 2
print(tennisWinner(6, 4))   # prints "1", since player 1 has won by 2
print(tennisWinner(25, 24))   # prints "0", since player 1 has not won by 2 (and they're both probably very tired!)

Be sure to include both the pseudocode and the Python code in your submission!

Part 3

Implement pseudocode for calculating the running average of numbers. While the user continues to input numbers (e.g. in a loop), keep the running average. When the user stops, emit the average of the numbers input. Be careful, the user may not input any numbers!

Now, implement this in Python. Here is some “skeleton code”:

def runningAverage():
    user_input = input("input a number")
    while user_input:
        ...

        user_input = input("input another number")
    ...

Be sure to include both the pseudocode and the Python code in your submission!