Problem Set 7 - Due Fri Dec 11 at 23:59

Reading

Slides and notebooks from:
- Lec 16 Intro to Recursion
- Lec 17 Fruitful Recursion
Lab 10 on recursion, and lab 11 on fruitful recursion.
Think Python, Ch. 5, Sections 5.8–5.10 on recursion, and Think Python, Ch. 6, Sections 6.5–6.9 on fruitful recursion.

About this Problem Set

This problem set will challenge your understanding of recursion, including fruitful recursion.

Task 0: Survey — Please fill out this anonymous survey to help us improve this course and learn more about how our teaching strategies worked or didn't work.
Task 1: Genetic Sequences — Use fruitful recursion to write some functions that process strings representing DNA sequences. For this problem, having a partner is optional but recommended.

If you want to find a partner to work with for this problem set, use this Piazza post to do so (we will mark old requests as closed when each new problem set is posted).

Notes

Each task has a rubric which you should use as a checklist to determine whether you have completed the task.
Reminder: Collaboration and honor code: you can talk with other individuals and teams about high-level problem-solving strategies, but you cannot share any code with them (unless you are working together on a partner problem).
If you are not going to be able to get everything done before the deadline, you may take a 24-hour extension on this problem set, no questions asked. To do so, you must click the "Take extension" button for this problem set in the Ocean Server before the deadline has passed. If it is close to the deadline and you don't know if you'll make it in time, consider taking the extension now, and then turn in your work. If you take an extension you will not receive feedback until the extended deadline has passed; note that the deadline for revisions does not change when you take an extension, so this gives you less time to revise your work.
The CS111 Problem Set Guide gives an overview of psets, including a detailed description of individual and partner tasks.
Follow the practices discussed in our CS111 Code Style Guide.
When you're done with the tasks follow the submission instructions to submit your pset.
All code for this assignment is available in the ps07 folder in the cs111/download directory within your cs server account.

Time Estimate

To help you plan how long you need to spend on this problem set, we have some guidelines based on how long students spent on these tasks last semester (please fill out your time estimates to help students in future semesters).

When you've been working on a task for about 2 hours, you should evaluate whether you are making efficient progress, and make use of some of the class resources available to you, like help-room hours or office hours. If you've been working on one task for 4 hours and still have a ways to go, you should definitely get some help with it.

The entire problem set will probably take you something like 2–4 hours of programming, plus another half hour to hour of reading, although some students take more or less time than that.

Tasks

The instructions for each task and their specific requirements are laid out on the following pages:

How to turn in this Problem Set

For task 1, each team member must submit their final genetics.py file to the Ocean server. It is not sufficient for your teammate to submit this task, you must both submit it independently, or you will not get credit. If you worked with a partner on this problem, this file should contain a comment with both of your names and usernames at the top, in addition to the submission date.
Upload each of your individual task files via the Ocean server by the deadline ( Fri Dec 11 at 23:59). Click on "Browse..." for the task that you're submitting, then once you've chosen your file, enter your time estimate and click on "Submit task". Note that you can submit as many times as you like, and we will only grade the last version you submit before the deadline, so it's a good idea to submit several times as you work on the assignment as a backup in case you accidentally lose your work: we can help you recover a file that you've submitted to the server. If you encounter any trouble submitting via the Ocean server, please email Peter Mawhorter with a copy of the files you're trying so submit so that we have a record of your submission if the submission server is running into issues.
Double-check the status of your submitted tasks (you may have to wait a minute or two after uploading). The server will identify any serious problems with your submission, and you should fix these. In general, always make sure that your task files run without errors in Thonny before submitting them. Note that only major errors are identified at submission time: your actual grade will not be available until the problem set is due.
Failure to submit a code file before the deadline will result in zero credit for that code on ps07. (If you do get a zero, you may always take advantage of the revision period to get a better score).