day_08.py

from helper import get_input

inp = get_input(day=8)

forest = [[int(x) for x in trees] for trees in inp]
m = len(forest)
n = len(forest[0])


def part_1():
    visible = set()

    for i in range(1, m - 1):
        left = [0] * n
        right = [0] * n

        left[0] = forest[i][0]
        for j in range(1, n):
            left[j] = max(left[j - 1], forest[i][j])

        right[-1] = forest[i][-1]
        for j in range(n - 2, -1, -1):
            right[j] = max(right[j + 1], forest[i][j])

        for j in range(1, n - 1):
            if forest[i][j] > left[j - 1] or forest[i][j] > right[j + 1]:
                visible.add((i, j))

    for j in range(1, n - 1):
        left = [0] * m
        right = [0] * m

        left[0] = forest[0][j]
        for i in range(1, m):
            left[i] = max(left[i - 1], forest[i][j])

        right[-1] = forest[-1][j]
        for i in range(m - 2, -1, -1):
            right[i] = max(right[i + 1], forest[i][j])

        for i in range(1, m - 1):
            if forest[i][j] > left[i - 1] or forest[i][j] > right[i + 1]:
                visible.add((i, j))
    return len(visible) + 2 * n + 2 * m - 4


def get_score(i, j):
    tree = forest[i][j]

    l, r, t, b = 0, 0, 0, 0

    _i = i - 1
    while _i >= 0 and tree >= forest[_i][j]:
        t += 1
        if tree == forest[_i][j]:
            break
        _i -= 1
    if _i >= 0 and tree != forest[_i][j]:
        t += 1

    _i = i + 1
    while _i < m and tree >= forest[_i][j]:
        b += 1
        if tree == forest[_i][j]:
            break
        _i += 1
    if _i < m and tree != forest[_i][j]:
        b += 1

    _j = j - 1
    while _j >= 0 and tree >= forest[i][_j]:
        l += 1
        if tree == forest[i][_j]:
            break
        _j -= 1

    if _j >= 0 and tree != forest[i][_j]:
        l += 1

    _j = j + 1
    while _j < n and tree >= forest[i][_j]:
        r += 1
        if tree == forest[i][_j]:
            break
        _j += 1
    if _j < n and tree != forest[i][_j]:
        r += 1

    return l * r * t * b


def part_2():
    res = 0
    for i in range(m):
        for j in range(n):
            score = get_score(i, j)
            res = max(res, score)
    return res


print(f"D08P1: {part_1()}")
print(f"D08P2: {part_2()}")