[HackerRank][Python] 2D Arrays

Task
Calculate the hourglass sum for every hourglass in A, then print the maximum hourglass sum.

Example

In the array shown above, the maximum hourglass sum is 7 for the hourglass in the top left corner.

Input Format

There are 6 lines of input, where each line contains 6 space-separated integers that describe the 2D Array A.

Constraints

• -9 <= A[i][j] <= 9
• 0 <= i, j <= 5

Output Format

Print the maximum hourglass sum in A.

if __name__ == '__main__':

    # Create an empty list to store the input array
    arr = []

    # Take input of 6 lines, where each line contains 6 integers separated by spaces
    for _ in range(6):
        arr.append(list(map(int, input().rstrip().split())))

    # Initialize the maximum sum to None, indicating that we haven't found any valid hourglass sum yet
    max_sum = None

    # Loop through all valid sub-arrays (indices 0 to 3 for both rows and columns)
    for i in range(4):
        for j in range(4):
            # Calculate hourglass sum using the formula: sum = top row + middle element + bottom row
            sum = arr[i][j] + arr[i][j+1] + arr[i][j+2] \
                    + arr[i+1][j+1] \
                    + arr[i+2][j] + arr[i+2][j+1] + arr[i+2][j+2]
            # Update maximum sum if the current sum is greater than the previous maximum sum
            if max_sum is None or sum > max_sum:
                max_sum = sum

    # Print the maximum sum
    print(max_sum)

In this code, we initialize max_sum to None to indicate that we haven't found any valid hourglass sum yet. We then loop through all valid sub-arrays and calculate the hourglass sum for each of them using the formula mentioned above. We then update the max_sum variable if the current sum is greater than the previous maximum sum. Finally, we print the max_sum variable.