# Go Counting

Count the scored points on a Go board.

In the game of go (also known as baduk, igo, cờ vây and wéiqí) points
are gained by completely encircling empty intersections with your
stones. The encircled intersections of a player are known as its
territory.

Write a function that determines the territory of each player. You may
assume that any stones that have been stranded in enemy territory have
already been taken off the board.

Write a function that determines the territory which includes a specified coordinate.

Multiple empty intersections may be encircled at once and for encircling
only horizontal and vertical neighbours count. In the following diagram
the stones which matter are marked "O" and the stones that don't are
marked "I" (ignored).  Empty spaces represent empty intersections.

```text
+----+
|IOOI|
|O  O|
|O OI|
|IOI |
+----+
```

To be more precise an empty intersection is part of a player's territory
if all of its neighbours are either stones of that player or empty
intersections that are part of that player's territory.

For more information see
[wikipedia](https://en.wikipedia.org/wiki/Go_%28game%29) or [Sensei's
Library](http://senseis.xmp.net/).

## Exception messages

Sometimes it is necessary to raise an exception. When you do this, you should include a meaningful error message to
indicate what the source of the error is. This makes your code more readable and helps significantly with debugging. Not
every exercise will require you to raise an exception, but for those that do, the tests will only pass if you include
a message.

To raise a message with an exception, just write it as an argument to the exception type. For example, instead of
`raise Exception`, you should write:

```python
raise Exception("Meaningful message indicating the source of the error")
```

## Running the tests

To run the tests, run the appropriate command below ([why they are different](https://github.com/pytest-dev/pytest/issues/1629#issue-161422224)):

- Python 2.7: `py.test go_counting_test.py`
- Python 3.3+: `pytest go_counting_test.py`

Alternatively, you can tell Python to run the pytest module (allowing the same command to be used regardless of Python version):
`python -m pytest go_counting_test.py`

### Common `pytest` options

- `-v` : enable verbose output
- `-x` : stop running tests on first failure
- `--ff` : run failures from previous test before running other test cases

For other options, see `python -m pytest -h`

## Submitting Exercises

Note that, when trying to submit an exercise, make sure the solution is in the `$EXERCISM_WORKSPACE/python/go-counting` directory.

You can find your Exercism workspace by running `exercism debug` and looking for the line that starts with `Workspace`.

For more detailed information about running tests, code style and linting,
please see the [help page](http://exercism.io/languages/python).

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.