adventofcode/2022/08/main.py

#!/usr/bin/env python
# -*- encoding: utf-8; py-indent-offset: 4 -*-

# Author: Sebastian Mark
# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)

# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string


def readinput():
    with open("input", "r", encoding="utf-8") as file:
        lines = [list(line.strip()) for line in file]
    return lines


def is_visible(trees: list, tree_y: int, tree_x: int) -> bool:
    height = len(trees)
    width = len(trees[0])

    # edges are always visible
    if not 0 < tree_y < height - 1 or not 0 < tree_x < width - 1:
        return True

    # check up, right, down, right
    directions = [(-1, 0), (0, 1), (1, 0), (0, -1)]
    for dy, dx in directions:
        nxty = tree_y + dy
        nxtx = tree_x + dx
        # continue to check in the direction til border
        is_biggest = True
        while 0 <= nxty < height and 0 <= nxtx < width:
            # check size, stop searching if bigger tree found
            if trees[tree_y][tree_x] <= trees[nxty][nxtx]:
                is_biggest = False
                break

            nxtx += dx
            nxty += dy

        if is_biggest:
            return True

    return False


def scenic_score(trees: list, tree_y: int, tree_x: int) -> int:
    height = len(trees)
    width = len(trees[0])

    score = 1

    # check up, right, down, right
    directions = [(-1, 0), (0, 1), (1, 0), (0, -1)]
    for dy, dx in directions:
        nxty = tree_y + dy
        nxtx = tree_x + dx
        visual_range = 1

        # continue to check in the direction til border
        while 0 < nxty < height - 1 and 0 < nxtx < width - 1:
            # check size, stop if bigger tree found
            if trees[tree_y][tree_x] <= trees[nxty][nxtx]:
                break

            visual_range += 1
            nxtx += dx
            nxty += dy

        score *= visual_range

    return score


def main():
    trees = readinput()

    # part 1
    visible = 0
    for y in range(len(trees)):
        for x in range(len(trees[0])):
            if is_visible(trees, y, x):
                visible += 1
    print("Visible trees: %d" % visible)

    # part 1
    scenic_scores = []
    for y in range(len(trees)):
        for x in range(len(trees[0])):
            scenic_scores.append(scenic_score(trees, y, x))
    print("Highest scenic score: %d" % max(scenic_scores))


if __name__ == "__main__":
    main()