create word search path retrieval with comprehensive doctests

[maknelso]

Describe your change:

I added a backtracking word search function that returns the path of the coordinates of each character or None if word cannot be found.

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request. N/A
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

[algorithms-keeper]

Click here to look at the relevant links ⬇️

🔗 Relevant Links

Repository:

• Contributing guidelines
• Project Euler solution guidelines

Python:

• Formatted string literals (f-strings)
• Type hints
• doctest
• unittest
• pytest

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[algorithms-keeper]

As there is no test file in this pull request nor any test function or class in the file backtracking/word_search_path.py, please provide doctest for the function get_word_path

[maknelso]

added doctests for get_word_path():

    """
    Return the coordinate path if it's possible to find the word in the grid.

    >>> board = [["C", "A", "T"], ["X", "Y", "S"], ["A", "B", "C"]]
    >>> # 1. Find "CATS" starting at (0,0). Initial key is 0.
    >>> get_word_path(board, "CATS", 0, 0, 0, {0}, [])
    [(0, 0), (0, 1), (0, 2), (1, 2)]
    
    >>> # 2. Find "BC" starting at (2,1). 
    >>> # Key for (2,1) in 3x3 is: (3 * 3 * 2) + 1 = 19
    >>> get_word_path(board, "BC", 2, 1, 0, {19}, [])
    [(2, 1), (2, 2)]
    
    >>> # 3. Partial search: current_path already has (0,0), looking for "ATS" starting at (0,1)
    >>> # Key for (0,1) is 1. Visited includes the 'C' at key 0.
    >>> get_word_path(board, "ATS", 0, 1, 0, {0, 1}, [(0, 0)])
    [(0, 0), (0, 1), (0, 2), (1, 2)]

    >>> # 4. Failure case: First letter doesn't match current cell
    >>> get_word_path(board, "DOG", 0, 0, 0, {0}, []) is None
    True
    """

[algorithms-keeper]

Click here to look at the relevant links ⬇️

🔗 Relevant Links

Repository:

• Contributing guidelines
• Project Euler solution guidelines

Python:

• Formatted string literals (f-strings)
• Type hints
• doctest
• unittest
• pytest

Automated review generated by algorithms-keeper. If there's any problem regarding this review, please open an issue about it.

---

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algorithms-keeper actions can be triggered by commenting on this PR:

• @algorithms-keeper review to trigger the checks for only added pull request files
• @algorithms-keeper review-all to trigger the checks for all the pull request files, including the modified files. As we cannot post review comments on lines not part of the diff, this command will post all the messages in one comment.

NOTE: Commands are in beta and so this feature is restricted only to a member or owner of the organization.

[algorithms-keeper]

As there is no test file in this pull request nor any test function or class in the file backtracking/word_search_path.py, please provide doctest for the function get_word_path

[maknelso]

added doctests for get_word_path():

    """
    Return the coordinate path if it's possible to find the word in the grid.

    >>> board = [["C", "A", "T"], ["X", "Y", "S"], ["A", "B", "C"]]
    >>> # 1. Find "CATS" starting at (0,0). Initial key is 0.
    >>> get_word_path(board, "CATS", 0, 0, 0, {0}, [])
    [(0, 0), (0, 1), (0, 2), (1, 2)]
    
    >>> # 2. Find "BC" starting at (2,1). 
    >>> # Key for (2,1) in 3x3 is: (3 * 3 * 2) + 1 = 19
    >>> get_word_path(board, "BC", 2, 1, 0, {19}, [])
    [(2, 1), (2, 2)]
    
    >>> # 3. Partial search: current_path already has (0,0), looking for "ATS" starting at (0,1)
    >>> # Key for (0,1) is 1. Visited includes the 'C' at key 0.
    >>> get_word_path(board, "ATS", 0, 1, 0, {0, 1}, [(0, 0)])
    [(0, 0), (0, 1), (0, 2), (1, 2)]

    >>> # 4. Failure case: First letter doesn't match current cell
    >>> get_word_path(board, "DOG", 0, 0, 0, {0}, []) is None
    True
    """

[algorithms-keeper]

Click here to look at the relevant links ⬇️

🔗 Relevant Links

Repository:

• Contributing guidelines
• Project Euler solution guidelines

Python:

• Formatted string literals (f-strings)
• Type hints
• doctest
• unittest
• pytest

Automated review generated by algorithms-keeper. If there's any problem regarding this review, please open an issue about it.

---

algorithms-keeper commands and options

algorithms-keeper actions can be triggered by commenting on this PR:

• @algorithms-keeper review to trigger the checks for only added pull request files
• @algorithms-keeper review-all to trigger the checks for all the pull request files, including the modified files. As we cannot post review comments on lines not part of the diff, this command will post all the messages in one comment.

NOTE: Commands are in beta and so this feature is restricted only to a member or owner of the organization.

[algorithms-keeper]

As there is no test file in this pull request nor any test function or class in the file backtracking/word_search_path.py, please provide doctest for the function get_word_path

[maknelso]

added doctests for get_word_path():

    """
    Return the coordinate path if it's possible to find the word in the grid.

    >>> board = [["C", "A", "T"], ["X", "Y", "S"], ["A", "B", "C"]]
    >>> # 1. Find "CATS" starting at (0,0). Initial key is 0.
    >>> get_word_path(board, "CATS", 0, 0, 0, {0}, [])
    [(0, 0), (0, 1), (0, 2), (1, 2)]
    
    >>> # 2. Find "BC" starting at (2,1). 
    >>> # Key for (2,1) in 3x3 is: (3 * 3 * 2) + 1 = 19
    >>> get_word_path(board, "BC", 2, 1, 0, {19}, [])
    [(2, 1), (2, 2)]
    
    >>> # 3. Partial search: current_path already has (0,0), looking for "ATS" starting at (0,1)
    >>> # Key for (0,1) is 1. Visited includes the 'C' at key 0.
    >>> get_word_path(board, "ATS", 0, 1, 0, {0, 1}, [(0, 0)])
    [(0, 0), (0, 1), (0, 2), (1, 2)]

    >>> # 4. Failure case: First letter doesn't match current cell
    >>> get_word_path(board, "DOG", 0, 0, 0, {0}, []) is None
    True
    """