# https://www.hackerrank.com/contests/projecteuler/challenges/euler011/problem
import numpy as np
from functools import reduce


def largest_product(matrix, length):
    matrix = np.asarray(matrix)
    rows, columns = matrix.shape
    max_product = float('-inf')

    for row in range(length, rows + 1):
        for column in range(length, columns + 1):
            matrix_partition = matrix[row - length:row, column - length:column]

            row_product = np.max(np.prod(matrix_partition, axis=0))
            column_product = np.max(np.prod(matrix_partition, axis=1))

            main_diagonal = np.diagonal(matrix_partition)
            main_diagonal_product = np.prod(main_diagonal)

            secondary_diagonal = np.fliplr(matrix_partition).diagonal()
            secondary_diagonal_product = np.prod(secondary_diagonal)

            max_product = max(
                [max_product, row_product, column_product, main_diagonal_product, secondary_diagonal_product])

    return max_product


def product(a, b):
    return a * b


def largest_product_low_level(matrix, length):
    rows, columns = len(matrix), len(matrix[0])
    max_product = float('-inf')

    for row in range(length, rows + 1):
        for column in range(length, columns + 1):
            matrix_partition = [row[column - length:column] for row in matrix[row - length:row]]

            row_product = max([reduce(product, r) for r in matrix_partition])
            column_product = max([reduce(product, c) for c in
                                  [[row[i] for row in matrix_partition] for i in range(len(matrix_partition[0]))]])

            main_diagonal_product = reduce(product, [matrix_partition[i][i] for i in range(len(matrix_partition))])

            secondary_diagonal_product = reduce(product, [matrix_partition[i][len(matrix_partition) - i - 1] for i in
                                                          range(len(matrix_partition))])

            max_product = max(
                [max_product, row_product, column_product, main_diagonal_product, secondary_diagonal_product])

    return max_product


if __name__ == "__main__":
    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'

    vector = [int(s) for s in grid.split(" ") if s != '']
    matrix = [vector[i:i + 20] for i in range(0, len(vector), 20)]

    print(np.asarray(matrix))
    print()
    print(largest_product(matrix, 4))
    print(largest_product_low_level(matrix, 4))
