Recursive Backtracking

Friday, May 3

Due Friday, May 3 at 11:59 PM

  • Submit to Paperless. Deadline is 11:59 PM.
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Last week's assignment introduced you to the intriguing world of recursion and built your base of recursive fundamentals. Now you move on to apply the power of recursive backtracking to solve real-world problems. As is typical in recursive problem-solving, the primary challenge is at the beginning as you work to develop the recursive insight, but once ready to write the code, a concise algorithm is all that's needed. That sparse elegance can sometimes seem incongruous with how hard you had to work for it. Start without delay to give yourself enough time to let these deep and powerful ideas percolate to full understanding. When you put the finishing touches on these problems, you will have earned your rightful place as a master in the way of recursive problem-solving.

This assignment is to be completed individually. Working in pairs/groups is not permitted.

Learning goals

After completing this assignment, you will be able to…

  • Appreciate the elegance and power of recursive problem-solving and identify problems that are well-suited to be solved recursively
  • Implement more advanced recursive algorithms to solve problems that cannot be easily solved using an iterative approach
  • Reflect thoughtfully on the ends to which you will apply these techniques

Assignment parts

This assignment consists of a warmup exercise and three separate problems to solve using recursive backtracking.

  • Warmup

    Practice with testing and debugging recursive functions.

  • Text Predict

    Predict a user's intended word when typed on old-style phone keypad.

  • Banzhaf power index

    Compute the voting power of the different blocks in a block-voting system.

  • Computational Redistricting

    Determine if there is a fair geometric division of a state's population into equal-size electoral districts.

Getting started

📦 Starter project

The starter project is provided as a zip archive. Download the zip, extract the files, and move the project folder to your CS106B folder. Open the .pro file in Qt Creator to get started.

Resources

Here are some resources that you might find helpful for this assignment:

Getting help

Look for an announcement on the Ed forum for the YEAH session for this assignment. We welcome your questions on the Ed forum. Always start by searching first to see if your question has already been answered before making a new post. To troubleshoot a problem with your specific code, your best bet is to bring it to the LaIR helper hours or office hours.

Submit

Before you call it done, run through our submit checklist to be sure all your ts are crossed and is dotted. Then upload your completed files to Paperless for grading.

Please submit only the files you edited; for this assignment, these files will be:

  • predict.cpp
  • voting.cpp
  • redistrict.cpp
  • short_answer.txt

🏁 Submit to Paperless

Note: On Paperless, all due dates and submission times are expressed in Pacific time.