AoC Day 8

day8.py

from functools import reduce
from itertools import chain


def determine_visibility(input):
    matrix = [[int(x) for x in b] for b in input]
    
    def look_up(current_position):
        x, y = current_position
        return [matrix[i][x] for i in reversed(range(y))]
    
    def look_down(current_position):
        x, y = current_position
        l = len(matrix[y])
        return [matrix[i][x] for i in range(y + 1, l)]
    
    def look_left(current_position):
        x, y = current_position
        return [matrix[y][i] for i in reversed(range(x))]
    
    def look_right(current_position):
        x, y = current_position
        l = len(matrix[x])
        return [matrix[y][i] for i in range(x + 1, l)]

    direction_functions = [look_up, look_down, look_left, look_right]
    matrix = [[int(x) for x in b] for b in input]

    result_matrix1, result_matrix2 = [], []
    for y, row in enumerate(matrix):
        result_1, result_2 = [], []
        for x, height in enumerate(row):
            current_position = [x, y]

            # Part 1
            for direction_function in direction_functions:
                direction_results = direction_function(current_position)
                if all(map(lambda x: x < height, direction_results)):
                    result_1.append('x')
                    break
            
            # Part 2
            counters = []
            for direction_function in direction_functions:
                counter = 0
                direction_results = direction_function(current_position)
                for direction_result in direction_results:
                    counter += 1
                    if direction_result >= height:
                        break
                counters.append(counter)

            result_1.append(height)
            result_2.append(reduce(lambda x, y: x * y, counters))
        
        result_matrix1.append(result_1)
        result_matrix2.append(result_2)


    return (
        len(
            list(
                chain(
                    *[list(filter(lambda x: x == 'x', i)) for i in result_matrix1]
                )
            )
        ),
        max(list(chain(*result_matrix2)))
    )


# Test 1
TEST_INPUT = ['30373', '25512', '65332', '33549', '35390']
assert determine_visibility(TEST_INPUT)[0] == 21

# Test 2
assert determine_visibility(TEST_INPUT)[1] == 8

# Result
with open('data/day8.txt') as _file:
    input = _file.read().splitlines()
    for i, result in enumerate(determine_visibility(input)):
        print(f'Part {i + 1}:', result)