problem_11.py

"""
Challenge 11 of project euler - Largest Product in a Grid

@author Ori Dabush
"""
from functools import reduce
from itertools import product
from operator import mul


GROUP_SIZE = 4
INPUT_GRID = [
    "08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08",
    "49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00",
    "81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65",
    "52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91",
    "22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80",
    "24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50",
    "32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70",
    "67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21",
    "24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72",
    "21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95",
    "78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92",
    "16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57",
    "86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58",
    "19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40",
    "04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66",
    "88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69",
    "04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36",
    "20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16",
    "20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54",
    "01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48",
]


def get_right_group(grid, i, j) -> list[int] | None:
    if i < 0 or j < 0:
        raise ValueError('Negative indexes')
    if j > len(grid[0]) - GROUP_SIZE:
        return None
    return grid[i][j:j + GROUP_SIZE]


def get_down_group(grid, i, j) -> list[int] | None:
    if i < 0 or j < 0:
        raise ValueError('Negative indexes')
    if i > len(grid) - GROUP_SIZE:
        return None
    return [grid_row[j] for grid_row in grid[i:i + GROUP_SIZE]]


def get_right_diagonal_group(grid, i, j) -> list[int] | None:
    if i < 0 or j < 0:
        raise ValueError('Negative indexes')
    if i > len(grid) - GROUP_SIZE or j > len(grid[0]) - GROUP_SIZE:
        return None
    return [grid_row[grid_col] for grid_row, grid_col in zip(grid[i:i + GROUP_SIZE], range(j, j + GROUP_SIZE))]


def get_left_diagonal_group(grid, i, j) -> list[int] | None:
    if i < 0 or j < 0:
        raise ValueError('Negative indexes')
    if i > len(grid) - GROUP_SIZE or j < GROUP_SIZE - 1:
        return None
    return [grid_row[grid_col] for grid_row, grid_col in zip(grid[i:i + GROUP_SIZE], range(j, j - GROUP_SIZE, -1))]


def solve():
    grid = [list(map(int, line.split(' '))) for line in INPUT_GRID]
    result = -1
    for i, j in product(range(len(grid)), range(len(grid[0]))):
        group = get_right_group(grid, i, j)
        if group:
            result = max(result, reduce(mul, group))
        group = get_down_group(grid, i, j)
        if group:
            result = max(result, reduce(mul, group))
        group = get_right_diagonal_group(grid, i, j)
        if group:
            result = max(result, reduce(mul, group))
        group = get_left_diagonal_group(grid, i, j)
        if group:
            result = max(result, reduce(mul, group))
    return result


def main():
    print(f'The answer is {solve()}')


if __name__ == '__main__':
    main()