HW1 | Anya E. Vostinar

Logistics

This is an individual assignment, so you should complete it on your own, though you are able to get help from many sources as detailed in the collaboration policy.

This assignment is worth 12 points total and is due on Wednesday Jan 12th at 10pm. See the syllabus for the late policy.

Goals

The goal of this assignment is two-fold: to get started with basic Python programming and also thinking algorithmically.

Setup

I recommend that you complete the programming portion of this assignment in Olin 310.

Mount the COURSES drive and remember to save everything into STUWORK. If you don’t do this, everything you write will disappear when you log out!!!!

Create a new folder in your STUWORK called HW1
Open your HW1 folder in VSCode
Create three files scrabble.txt, helloworld.py, and input.py.

If you really want to use your personal machine, there are instructions for installing VSCode and Python available: Mac and Windows. You can also remotely connect to COURSES. If you run into trouble with these setups, you can ask me or Mike Tie for help, but I do really recommend just working in Olin 310.

Scrabble

Even before you’ve learned about Python, you can still continue working on thinking algorithmically by coming up with another algorithm written in English.

The game of Scrabble is a word game in which players form words from a collection of tiles in their hand. I play this game with my father-in-law every time we visit and so need to develop some good strategies for winning. In the game, the first player draws a “hand” of seven tiles, each of which has a letter printed on it. The person aims to form a legal word — one found in the official Scrabble dictionary (which has some very strange words for the record) — worth as many points as possible. A bingo is a play that uses all seven tiles in the player’s hand. The Scrabble scoring system strongly rewards bingos (because they are really hard to get). For example, if you are dealt the hand

|N| |T| |H| |P| |O| |S| |Y|

then you can play a bingo (the word PYTHONS), but if you are dealt the hand

|C| |A| |R| |L| |E| |T| |O|

then there’s no bingo play available. (It’s harder to persuade you that this hand is a “no” than it was to persuade you that the previous hand is a “yes,” but it is, I promise). Describe, in as much detail as necessary to be completely clear, an algorithm that determines whether a given hand of seven tiles can be played as a bingo. Do not give instructions like “try all the different orderings of the tiles in the hand and see if any of them are words”; instead, tell me how to figure out every step. You should assume that I have a very bad memory, but plenty of scratch paper; tell me what to write down (or read from my notes) as I look at the tiles. You should assume that I have access to a dictionary, but I don’t remember how to use it well. In particular, you should assume that I can do the following kinds of things reliably:

turn pages in the dictionary.
remember a few words (or any sequence of up to ten letters) in my head.
recognize a word that I’m remembering when I see it.
write things down on a piece of scrap paper.
use my fingers to keep track of where I am in the dictionary, tiles, or on a piece of scrap paper.

Later in the term you will have a chance to implement an algorithm for this problem in Python, but for now I want you to describe in English how to solve this problem.

Hello World

In helloworld.py type out the following (don’t copy and paste, copying even comments in Python often leads to weird errors):
```
# helloworld.py
# CS 111, Winter 2022
# This is the traditional first program to write in any programming language.
```
This is a header. The lines that begin with # are comments, which are ignored when your program is being executed. (They’re there to help people who are reading the program understand what it’s doing.) You should include a similar header on all programs you submit for this class (and in general). Such headers and comments will contribute to your style points for an assignment.
Now make it so that when the program runs, it prints out the following exactly:
```
Hello, world!
```
When I say exact, I mean exact. In this class, I have written autograders for most assignments, which run on your code as soon as you submit it and let you know if you are passing the tests that I’ve written. Those tests check if your output matches what I’ve specified down to the spaces, so it’s very important that you follow my specifications exactly. (This may seem annoying, but it is a valuable skill to master. It is very common in computer science for you to have very specific instructions that you need to follow for something to work or for a client to be happy.) The benefit of the autograders is that you can know right away if you code isn’t doing exactly the right thing and fix it before the deadline!
You should always check that your code works after writing a small piece, so open a Terminal window in VSCode (either by clicking ‘Terminal’->’New Terminal’ from the menu at the top or by dragging up from the bottom of your screen) and type the following:
```
python3 helloworld.py
```
Make sure that it matches the above output exactly.

Input

Now you’ll do some more complicated tasks in Python. Everything that I ask of you here is something that you can accomplish with just the code that you’ve seen in Zelle 1.6-1.7.

Create a header for your file (you don’t know what it does yet, so remember to go fill that in once you’ve figured that out)
Have your program print the following by storing the year in a variable:
```
It is currently the year 2021
```
Next have your program ask for the user’s name:
```
What is your name? 
```
Next have your program greet the user by name:
```
Hi, <name>
```
Remember to test your program after every chunk of code that you write to make sure it is working. This is what you should have so far, if your name is Anya:
```
$python3 input.py
It is currently the year 2021
What is your name? Anya
Hi, Anya
```
Next have your program ask the user’s age:
```
How old are you?
```
Next have your program print the square of the user’s age:
```
The square of your age is <value>
```

This is a good time to check to make sure your code is working correctly again:

$ python3 input.py
It is currently the year 2021
What is your name? Anya
Hi, Anya
How old are you? 200
The square of your age is 40000

Now have your program also print out the following:
```
You are now twice the age you were in <answer>
```
One slightly strange thing that you might have noticed is that you might be being told a year that’s represented using a decimal point, which is probably not how you think of years. (Was the Magna Carta really signed in year 1215.0?) We’ll talk about this issue more in a little while — it’s related to the way that numbers are stored internally in Python — but you can fix it right now. Instead of printing the value of currentYear - age/2 for example, you can print the value of currentYear - int(age/2), or int(currentYear - age/2). The function int stands for integer, and it converts any number it’s given into an integer. (The function int is “generous” about your age: it rounds down.) You should go with the later year if they are an odd-numbered year.

You should now get the following:

$python3 input.py
It is currently the year 2022
What is your name? Anya
Hi, Anya
How old are you? 200
The square of your age is 40000
You are now twice the age you were in 1922

Also print out the year that the user will be twice their current age:
```
You will be twice your current age in <year>
```
Finally, have your program print out the first U.S. presidential election in which the user could vote. (Assume that the user’s birthday is not between today and Election Day, the second Tuesday in November, and that the user is otherwise eligible to vote.) This calculation is a bit trickier in its logic, because: 1) a voter must be 18 years old to vote. 2) Presidential elections happen only every four years, in years that are divisible by 4 (like 2008 or 2020, because 2008 = 502 * 4 and 2020 = 505 * 4).

You’ll have to figure out a formula to express the first year that the user is at least 18 years old and the year is divisible by 4. (Yes, you could look up some more advanced features of Python to accomplish this task, and it’s fine to — but I also promise that you can do it using only the elements from this problem set.) Here’s a small hint (about decades instead, but still relevant):

year = 2021
decade = int(year / 10)
print("I love the", decade, "0s.")

# Or, for comparison, with better spacing:
print("I love the " + str(decade) + "0s.")

Here is the final output that your program should handle:

$ python3 input.py
It is currently the year 2022
What is your name? Anya
Hi, Anya
How old are you? 200
The square of your age is 40000
You are now twice the age you were in 1922
You will be twice your current age in 2222
Eligible to vote in: 1840

Any program with more than a few lines of code (so nearly all of them), should have comments describing what blocks of the code do. We’ll learn more about how to better organize code in the future, but for now you should put in a couple of comments describing what blocks of code are doing so that someone reading your program can easily see what is going on. You should also make sure any variables you used are named well and make sure your header describes what the program does. Finally, be mindful of the spacing in your program: how can you use an extra line here or there to make it easier to read, but not too many? There are several right answers to these style questions, so go with what you think makes it easiest to read and stay consistent. The graders will give feedback on style to help you improve it.

Rubric

Your assignment will be graded with the following rubric:

Item	Points
Well-described Scrabble algorithm	4
Passes programming tests	4
Style (header, comments, variable names, spacing)	4

Submission

You should submit your three files through the Gradescope link on Moodle for this assignment. You are able to upload them individually to Gradescope, at which point the autograder will run and let you know if your code works correctly. You are able to submit your code as many times as you wish before the deadline to fix any issues. If you have questions about what the autograder is telling you is wrong, please ask!