Hackerank: Interview Prep Kit: 2D Arrays — DS

Hi, to we’d be solving a problem that has to do with arrays, please make sure to understand the problem before taking the solution.

Problem

Given 6 x 6 2D Array, arr:
1 1 1 0 0 0
0 1 0 0 0 0
1 1 1 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
An hourglass in A is a subset of values with indices in this pattern in arr's graphical representation:
a b c
  d 
e f g
There are 16 hourglasses in arr. An hourglass sum is the sum of an hourglass' values. Calculate the hourglass sum for every hourglass in arr, then print the maximum hourglass sum. The array will always be 6 x 6

Example

arr =
-9 -9 -9  1 1 1
 0 -9  0  4 3 2
-9 -9 -9  1 2 3
 0  0  8  6 6 0
 0  0  0 -2 0 0
 0  0  1  2 4 0
The 16 hourglass sums are:
-63, -34, -9, 12, 
-10,   0, 28, 23, 
-27, -11, -2, 10, 
  9,  17, 25, 18
The highest hourglass sum is 28 from the hourglass beginning at row 1, column 2;
0 4 3
  1
8 6 6
Note: If you have already solved the Java domain's java 2D Array challenge, you may wish to skip this challenge

Function Description

Complete the function hourglassSum in the editor below:
hourglassSum has the following parameter(s):
* int arr[6][6]: an array of integers

Returns

* int: the maximum hourglass sum

Input Format

Each of the 6 lines of inputs arr[i] contains 6 space-separated integers arr[i][j]

Output format

Print the largest (maximum) hourglass sum found in arr

Sample Input

1 1 1 0 0 0
0 1 0 0 0 0
1 1 1 0 0 0
0 0 2 4 4 0
0 0 0 2 0 0
0 0 1 2 4 0

Sample Output

19

Explanation

arr contains the following hourglasses:

The hourglass with the maximum sum (19)is:
2 4 4
  2
1 2 4

Solution in Dart:

Solution in Javascript

So, there you go, if you have questions or disagreements or a better way to solve this problem, please reach out to me here or on LinkedIn or Twitter, I will be more than happy to engage with you.