distance.py

def calculate_distance_one_point(city, position, cache, value=-1):
    row, col = position

    if (row, col) in cache:
        print( f"Already {row} {col}" )
        return None
    cache.add((row, col))

    print("doing", row, col)

    if row < 0 or col < 0 or row >= len(city) or col >= len(city[0]):
        print( f"Limits {row} {col}" )
        return None

    cell = city[row][col]

    if cell == "X":
        return None

    if cell == "D":
        print(row, col, "D", value, "+1")
        return value + 1

    if cell == " ":
        print(" space ", row, col, "S", value, "+1")

        results = []
        results.append( calculate_distance_one_point(city, [row - 1, col], cache.copy(), value+1) )
        results.append( calculate_distance_one_point(city, [row, col + 1], cache.copy(), value+1) )
        results.append( calculate_distance_one_point(city, [row + 1, col], cache.copy(), value+1) )
        results.append( calculate_distance_one_point(city, [row, col - 1], cache.copy(), value+1) )
        results = [r for r in results if r is not None]

        print("results", results)

        if not results:
            return None
        else:
            return min(results)


def calculate_distance(city, positions):
    results = []
    for position in positions:
        cache = set()
        result = calculate_distance_one_point(city, position, cache)
        results.append( -1 if result is None else result )
    return results


def test_distance_curve3():
    city = [
        ["D", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", "D", " "],
        [" ", " ", "X", "D", " "],
    ]

    positions = [
        [1, 1],
    ]

    result = calculate_distance(city, positions)

    assert result == [2]


def test_distance_curve2():
    city = [
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", "D", " "],
        [" ", " ", "X", "D", " "],
    ]

    positions = [
        [1, 1],
    ]

    result = calculate_distance(city, positions)

    assert result == [3]


def test_distance_right():
    city = [
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", "D", " "],
        [" ", " ", "X", "D", " "],
    ]

    positions = [
        [2, 1],
    ]

    result = calculate_distance(city, positions)

    assert result == [2]


def test_distance_left():
    city = [
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", "D", " ", " ", " "],
        [" ", " ", " ", " ", " "],
    ]

    positions = [
        [2, 3],
    ]

    result = calculate_distance(city, positions)

    assert result == [2]


def test_distance_top():
    city = [
        [" ", "D", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
    ]

    positions = [
        [3, 1],
    ]

    result = calculate_distance(city, positions)

    assert result == [3]


def test_distance_bottom():
    city = [
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", "D", " ", " ", " "],
    ]

    positions = [
        [0, 1],
    ]

    result = calculate_distance(city, positions)

    assert result == [3]


def test_distance_blocked1():
    city = [
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", "X", " "],
        [" ", " ", "X", "D", "X"],
    ]

    positions = [
        [2, 4],
    ]

    result = calculate_distance(city, positions)

    assert result == [-1]


def test_distance_blocked2():
    city = [
        ["D", " ", " ", " ", " "],
        [" ", " ", " ", " ", " "],
        [" ", " ", " ", "X", " "],
        [" ", " ", "X", "D", "X"],
    ]

    positions = [
        [2, 4],
    ]

    result = calculate_distance(city, positions)

    assert result == [6]