CSCI-1200/hws/inverse_word_search

Special Note 1: A correct program does not necessarily pass all the test cases for this assignment, as Submitty may let you fail a test case if your program is not fast enough or consumes too much memory.

Homework 6 — Inverse Word Search Recursion

In this homework we will build an inverse word search program using the techniques of recursion. The goal is to construct a grid of letters that one can search to find specific words. Understanding the non-linear word search program from Lectures 12/13 will be helpful in thinking about how you will solve this problem. We strongly urge you to study and play with that program, including tracing through its behavior using a debugger or cout statements or both. Please read the entire handout before beginning your implementation.

Your Tasks

For this assignment, you will be given the dimensions (width and height) of a word search puzzle, a set of words that should appear in the grid (forwards, backwards, up, down, or along any diagonal), and optionally a set of words that should not appear anywhere in the grid. Each grid cell will be assigned one of the 26 lowercase letters. Note that unlike the non-linear word search problem we discussed in class, we will only allow words that appear in a straight line (including diagonals). Your task is to output all unique word search grids that satisfy the requirements. Rotations and mirroring of the board will be considered unique solutions.

Your program should expect three command line arguments, the name of the input file, the name of the output file, and a string:

inverse_word_search.exe puzzle2.txt out2.txt one_solution
inverse_word_search.exe puzzle2.txt out2.txt all_solutions

The third argument indicates whether the program should find all solutions, or just one solution. Here’s an example of the input file format:

The first line specifies the width and height of the grid. Then each line that follows contains a character and a word. If the character is ’+’, then the word must appear in the grid. If the character is ’-’, then the word must not appear in the grid. For this first example we show an incorrect solution on the left. Though it contains the 4 required words, it also contains two of the forbidden words. The solution on the right is a fully correct solution. This particular problem has 8 solutions including rotations and reflections.

Below is a second example that specifies only positive (required) words. This puzzle has 4 solutions including rotations and reflections.

When asked to find all solutions, your program should first output the number of solutions and then an ASCII representation for each solution. See the example output files provided in this folder. You should follow this output closely, however your solutions may be listed in a different order. When asked to find just one solution, your program should just output the first legal solution it finds (it does not need to count the number of solutions, nor does it need to be the first solution shown in our output). If the puzzle is impossible your program should output “No solutions found”.

To implement this assignment, you must use recursion in your search. First you should tackle the problem of finding and outputting one legal solution to the puzzle (if one exists).

Program Requirements & Submission Details

Use good coding style when you design and implement your program. Organize your program into functions: don’t put all the code in main! Be sure to read the Homework Policies as you put the finishing touches on your solution. Be sure to make up new test cases to fully debug your program and don’t forget to comment your code! Use the provided template README.txt file for notes you want the grader to read. You must do this assignment on your own, as described in the Collaboration Policy & Academic Integrity page. If you did discuss the problem or error messages, etc. with anyone, please list their names in your README.txt file.

Due Date: 03/13/2025, Thursday, 10pm.

FAQs

1. Q: Am I allowed to use data structures not covered in this class?
   A: Yes. For this homework, you can use whatever data structures you want to use; but last year, the student who topped the leaderboard with a very large margin, did not use any fancy data structures. The student used std::set, but did not use std::unordered_set or std::unordered_map, or any data structures which had not been covered in this class.

2. Q: Can I use global variables for this homework?
   A: Yes, you can.

3. Q: Do I have to implement a class or classes?
   A: It's not a requirement. You can if you want to.

4. Q: Which optimization flag does the Submitty compiler use?
   A: Submitty uses -O3 for this homework.

5. Q: How many submissions can I make?
   A: 40. Submitty will deduct points once you submit more than 40 times.

6. Q: If I fill in all the words in the grid and there are still some empty slots, what characters do I fill in the these extra spaces?
   A: You can fill in any lower case letter there and make sure it doesn't introduce a forbidden word. A single letter gives you one solution; replacing it with another letter would give you another solution, and in total, this would lead to 26 potential solutions, since there are 26 lower case letters.

7. Q: What bonus do I get if my program ranks higher than the instructor's program on the leaderboard?
   A: If by Thursday night 10pm (which is the submission deadline), your program ranks higher than the instructor's program, you have many options. You can choose one of these:

• Drop the lowest test score

• Drop the lowest homework

• Skip 1 future homework

• Skip test 3

  You will receive an email asking you about which option you want to choose, or if you want to propose a different option.

Rubric

20 pts

• README.txt Completed (3 pts)
  • One of name, collaborators, or hours not filled in. (-1)
  • Two or more of name, collaborators, or hours not filled in. (-2)
  • No reflection. (-1)

• USES RECURSION (10 pts)
  • Use some non-trivial recursion but doesn’t use recursion in the search process of board creation. (-3)
  • Uses recursion but only trivially. (-7)
  • Does not use any recursion. (-10)

• PROGRAM STRUCTURE (7 pts)
  • Putting almost everything in the main function. It's better to create separate functions for different tasks. (-2)
  • Function bodies containing more than one statement are placed in the .h file. (okay for templated classes) (-2)
  • Functions are not well documented or are poorly commented, in either the .h or the .cpp file. (-1)
  • Improper uses or omissions of const and reference. (-1)
  • At least one function is excessively long (i.e., more than 200 lines). (-1)
  • Poor file organization: Puts more than one class in a file (okay for very small helper classes) (-1)
  • Poor choice of variable names: non-descriptive names (e.g. 'vec', 'str', 'var'), single-letter variable names (except single loop counter), etc. (-2)