Spiral Matrix

spiral-matrix/.exercism/config.json

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+{
+  "authors": [
+    "chgraef"
+  ],
+  "contributors": [
+    "cmccandless",
+    "crsmi",
+    "Dog",
+    "Grociu",
+    "tqa236"
+  ],
+  "files": {
+    "solution": [
+      "spiral_matrix.py"
+    ],
+    "test": [
+      "spiral_matrix_test.py"
+    ],
+    "example": [
+      ".meta/example.py"
+    ]
+  },
+  "blurb": "Given the size, return a square matrix of numbers in spiral order.",
+  "source": "Reddit r/dailyprogrammer challenge #320 [Easy] Spiral Ascension.",
+  "source_url": "https://web.archive.org/web/20230607064729/https://old.reddit.com/r/dailyprogrammer/comments/6i60lr/20170619_challenge_320_easy_spiral_ascension/"
+}

spiral-matrix/.exercism/metadata.json

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+{"track":"python","exercise":"spiral-matrix","id":"647e951a88314fe9bc3026ffbd670954","url":"https://exercism.org/tracks/python/exercises/spiral-matrix","handle":"myFirstCode","is_requester":true,"auto_approve":false}

spiral-matrix/HELP.md

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+# Help
+
+## Running the tests
+
+We use [pytest][pytest: Getting Started Guide] as our website test runner.
+You will need to install `pytest` on your development machine if you want to run tests for the Python track locally.
+You should also install the following `pytest` plugins:
+
+- [pytest-cache][pytest-cache]
+- [pytest-subtests][pytest-subtests]
+
+Extended information can be found in our website [Python testing guide][Python track tests page].
+
+
+### Running Tests
+
+To run the included tests, navigate to the folder where the exercise is stored using `cd` in your terminal (_replace `{exercise-folder-location}` below with your path_).
+Test files usually end in `_test.py`, and are the same tests that run on the website when a solution is uploaded.
+
+Linux/MacOS
+```bash
+$ cd {path/to/exercise-folder-location}
+```
+
+Windows
+```powershell
+PS C:\Users\foobar> cd {path\to\exercise-folder-location}
+```
+
+<br>
+
+Next, run the `pytest` command in your terminal, replacing `{exercise_test.py}` with the name of the test file:
+
+Linux/MacOS
+```bash
+$ python3 -m pytest -o markers=task {exercise_test.py}
+==================== 7 passed in 0.08s ====================
+```
+
+Windows
+```powershell
+PS C:\Users\foobar> py -m pytest -o markers=task {exercise_test.py}
+==================== 7 passed in 0.08s ====================
+```
+
+
+### Common options
+- `-o` : override default `pytest.ini` (_you can use this to avoid marker warnings_)
+- `-v` : enable verbose output.
+- `-x` : stop running tests on first failure.
+- `--ff` : run failures from previous test before running other test cases.
+
+For additional options, use `python3 -m pytest -h` or `py -m pytest -h`.
+
+
+### Fixing warnings
+
+If you do not use `pytest -o markers=task` when invoking `pytest`, you might receive a `PytestUnknownMarkWarning` for tests that use our new syntax:
+
+```bash
+PytestUnknownMarkWarning: Unknown pytest.mark.task - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/stable/mark.html
+```
+
+To avoid typing `pytest -o markers=task` for every test you run, you can use a `pytest.ini` configuration file.
+We have made one that can be downloaded from the top level of the Python track directory: [pytest.ini][pytest.ini].
+
+You can also create your own `pytest.ini` file with the following content:
+
+```ini
+[pytest]
+markers =
+    task: A concept exercise task.
+```
+
+Placing the `pytest.ini` file in the _root_ or _working_ directory for your Python track exercises will register the marks and stop the warnings.
+More information on pytest marks can be found in the `pytest` documentation on [marking test functions][pytest: marking test functions with attributes] and the `pytest` documentation on [working with custom markers][pytest: working with custom markers].
+
+Information on customizing pytest configurations can be found in the `pytest` documentation on [configuration file formats][pytest: configuration file formats].
+
+
+### Extending your IDE or Code Editor
+
+Many IDEs and code editors have built-in support for using `pytest` and other code quality tools.
+Some community-sourced options can be found on our [Python track tools page][Python track tools page].
+
+[Pytest: Getting Started Guide]: https://docs.pytest.org/en/latest/getting-started.html
+[Python track tools page]: https://exercism.org/docs/tracks/python/tools
+[Python track tests page]: https://exercism.org/docs/tracks/python/tests
+[pytest-cache]:http://pythonhosted.org/pytest-cache/
+[pytest-subtests]:https://github.com/pytest-dev/pytest-subtests
+[pytest.ini]: https://github.com/exercism/python/blob/main/pytest.ini
+[pytest: configuration file formats]: https://docs.pytest.org/en/6.2.x/customize.html#configuration-file-formats
+[pytest: marking test functions with attributes]: https://docs.pytest.org/en/6.2.x/mark.html#raising-errors-on-unknown-marks
+[pytest: working with custom markers]: https://docs.pytest.org/en/6.2.x/example/markers.html#working-with-custom-markers
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit spiral_matrix.py` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Python track's documentation](https://exercism.org/docs/tracks/python)
+- The [Python track's programming category on the forum](https://forum.exercism.org/c/programming/python)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+Below are some resources for getting help if you run into trouble:
+
+- [The PSF](https://www.python.org) hosts Python downloads, documentation, and community resources.
+- [The Exercism Community on Discord](https://exercism.org/r/discord)
+- [Python Community on Discord](https://pythondiscord.com/) is a very helpful and active community.
+- [/r/learnpython/](https://www.reddit.com/r/learnpython/) is a subreddit designed for Python learners.
+- [#python on Libera.chat](https://www.python.org/community/irc/) this is where the core developers for the language hang out and get work done.
+- [Python Community Forums](https://discuss.python.org/)
+- [Free Code Camp Community Forums](https://forum.freecodecamp.org/)
+- [CodeNewbie Community Help Tag](https://community.codenewbie.org/t/help)
+- [Pythontutor](http://pythontutor.com/) for stepping through small code snippets visually.
+
+Additionally, [StackOverflow](http://stackoverflow.com/questions/tagged/python) is a good spot to search for your problem/question to see if it has been answered already.
+ If not - you can always [ask](https://stackoverflow.com/help/how-to-ask) or [answer](https://stackoverflow.com/help/how-to-answer) someone else's question.

spiral-matrix/README.md

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+# Spiral Matrix
+
+Welcome to Spiral Matrix on Exercism's Python Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Introduction
+
+In a small village near an ancient forest, there was a legend of a hidden treasure buried deep within the woods.
+Despite numerous attempts, no one had ever succeeded in finding it.
+This was about to change, however, thanks to a young explorer named Elara.
+She had discovered an old document containing instructions on how to locate the treasure.
+Using these instructions, Elara was able to draw a map that revealed the path to the treasure.
+
+To her surprise, the path followed a peculiar clockwise spiral.
+It was no wonder no one had been able to find the treasure before!
+With the map in hand, Elara embarks on her journey to uncover the hidden treasure.
+
+## Instructions
+
+Your task is to return a square matrix of a given size.
+
+The matrix should be filled with natural numbers, starting from 1 in the top-left corner, increasing in an inward, clockwise spiral order, like these examples:
+
+## Examples
+
+### Spiral matrix of size 3
+
+```text
+1 2 3
+8 9 4
+7 6 5
+```
+
+### Spiral matrix of size 4
+
+```text
+ 1  2  3 4
+12 13 14 5
+11 16 15 6
+10  9  8 7
+```
+
+## Source
+
+### Created by
+
+- @chgraef
+
+### Contributed to by
+
+- @cmccandless
+- @crsmi
+- @Dog
+- @Grociu
+- @tqa236
+
+### Based on
+
+Reddit r/dailyprogrammer challenge #320 [Easy] Spiral Ascension. - https://web.archive.org/web/20230607064729/https://old.reddit.com/r/dailyprogrammer/comments/6i60lr/20170619_challenge_320_easy_spiral_ascension/

spiral-matrix/spiral_matrix.py

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+"""
+Generate a square spiral matrix.
+
+The matrix is filled with natural numbers starting at 1 in the top-left
+corner and increasing in an inward, clockwise spiral order.
+
+This module exposes a public function to build the spiral and some
+internal helpers used to track direction and position.
+"""
+
+DIRECTIONS: dict = {
+    "right": {"row": 0, "col": 1, "next_direction": "down"},
+    "left": {"row": 0, "col": -1, "next_direction": "up"},
+    "up": {"row": -1, "col": 0, "next_direction": "right"},
+    "down": {"row": 1, "col": 0, "next_direction": "left"},
+}
+
+
+def spiral_matrix(size: int) -> list[list[int]]:
+    """
+    Build a square matrix filled in clockwise spiral order.
+
+    :param size: The dimension of the square matrix to generate. Must be a
+                 non-negative integer. A size of 0 returns an empty list.
+    :return: A two-dimensional list representing the spiral matrix of shape
+            ``size x size``. Each cell contains a natural number starting at
+            1 and increasing as the spiral proceeds clockwise inward.
+    """
+    # Set initial data
+    result: list = [[0] * size for _ in range(size)]
+    num: int = 1
+    max_num: int = size * size
+    direction: str = "right"
+    x_y: list[int] = [0, 0]
+
+    # Create a square matrix
+    while num <= max_num:
+        result[x_y[0]][x_y[1]] = num
+        direction = _set_direction(direction, result, x_y, size)
+        x_y[0] += DIRECTIONS[direction]["row"]
+        x_y[1] += DIRECTIONS[direction]["col"]
+        num += 1
+
+    return result
+
+
+def _set_direction(
+    direction: str, result: list[list[int]], x_y: list[int], size: int
+) -> str:
+    """
+    Determine the next movement direction based on bounds and visited cells.
+
+    :param direction: next direction, one of {"right", "left", "up", "down"}.
+    :param result: The current matrix being filled.
+    :param x_y: Current coordinates as [row, col].
+    :param size: Dimension of the square matrix.
+    :return: The direction to move next so that the spiral proceeds without
+             leaving bounds or revisiting filled cells.
+    """
+    row, col = x_y
+    if direction == "right" and not (
+        col + 1 < size and result[row][col + 1] == 0
+    ):
+        direction = DIRECTIONS[direction]["next_direction"]
+    elif direction == "down" and not (
+        row + 1 < size and result[row + 1][col] == 0
+    ):
+        direction = DIRECTIONS[direction]["next_direction"]
+    elif direction == "up" and not (
+        row - 1 >= 0 and result[row - 1][col] == 0
+    ):
+        direction = DIRECTIONS[direction]["next_direction"]
+    elif direction == "left" and not (
+        col - 1 >= 0 and result[row][col - 1] == 0
+    ):
+        direction = DIRECTIONS[direction]["next_direction"]
+
+    return direction

spiral-matrix/spiral_matrix_test.py

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+# pylint: disable=C0301, C0114, C0115, C0116, R0904
+# These tests are auto-generated with test data from:
+# https://github.com/exercism/problem-specifications/tree/main/exercises/spiral-matrix/canonical-data.json
+# File last updated on 2023-07-19
+
+import unittest
+
+from spiral_matrix import (
+    spiral_matrix,
+)
+
+
+class SpiralMatrixTest(unittest.TestCase):
+    def test_empty_spiral(self):
+        self.assertEqual(spiral_matrix(0), [])
+
+    def test_trivial_spiral(self):
+        self.assertEqual(spiral_matrix(1), [[1]])
+
+    def test_spiral_of_size_2(self):
+        self.assertEqual(spiral_matrix(2), [[1, 2], [4, 3]])
+
+    def test_spiral_of_size_3(self):
+        self.assertEqual(spiral_matrix(3), [ [1, 2, 3],
+                                                    [8, 9, 4],
+                                                    [7, 6, 5]])
+
+    def test_spiral_of_size_4(self):
+        self.assertEqual(
+            spiral_matrix(4),
+            [[1, 2, 3, 4], [12, 13, 14, 5], [11, 16, 15, 6], [10, 9, 8, 7]],
+        )
+
+    def test_spiral_of_size_5(self):
+        self.assertEqual(
+            spiral_matrix(5),
+            [
+                [1, 2, 3, 4, 5],
+                [16, 17, 18, 19, 6],
+                [15, 24, 25, 20, 7],
+                [14, 23, 22, 21, 8],
+                [13, 12, 11, 10, 9],
+            ],
+        )