jae-l
6/2/2017 - 11:38 AM

## Example of how to find the sub-matrix of size 2 by 2 with the highest sum in a multidimensional array. From Fundamentals of Computer Program

Example of how to find the sub-matrix of size 2 by 2 with the highest sum in a multidimensional array. From Fundamentals of Computer Programming with C# http://www.introprogramming.info/wp-content/uploads/2013/07/Books/CSharpEn/Fundamentals-of-Computer-Programming-with-CSharp-Nakov-eBook-v2013.pdf

``````// Declare and initialize the matrix
int[,] matrix = {
{ 0, 2, 4, 0, 9, 5 },
{ 7, 1, 3, 3, 2, 1 },
{ 1, 3, 9, 8, 5, 6 },
{ 4, 6, 7, 9, 1, 0 }
};

// Find the maximal sum platform of size 2 x 2
long bestSum = long.MinValue;
int bestRow = 0;
int bestCol = 0;

for (int row = 0; row < matrix.GetLength(0) - 1; row++)
{
for (int col = 0; col < matrix.GetLength(1) - 1; col++)
{
long sum = matrix[row, col] + matrix[row, col + 1] +
matrix[row + 1, col] + matrix[row + 1, col + 1];
if (sum > bestSum)
{
bestSum = sum;
bestRow = row;
bestCol = col;
}
}
}

// Print the result
Console.WriteLine("The best platform is:");
Console.WriteLine(" {0} {1}",
matrix[bestRow, bestCol],
matrix[bestRow, bestCol + 1]);
Console.WriteLine(" {0} {1}",
matrix[bestRow + 1, bestCol],
matrix[bestRow + 1, bestCol + 1]);
Console.WriteLine("The maximal sum is: {0}", bestSum);

//  The best platform is:
//  9 8
//  7 9
//  The maximal sum is: 33``````