How to print the diagonals of a matrix not from left to right?

Question

Mathematics

I solve the problem of finding sequences of identical balls on the diagonals.
There is a code for displaying / passing along the diagonals of the matrix from left to right, from top to bottom.

int size = 9; //Размер матрицы 9x9
string diagonal  = "";
for (int k = 0; k < size * 2; k++)
{
   for (int j = 0; j <= k; j++)
   {
      int i = k - j;
      if (i < size && j < size)
      {
         diagonal += mat[j, i] + " ";
      }
   }
   print(diagonal);
   diagonal = "";
}

Now I'm trying to draw the diagonals from top to bottom, from right to left, in order to view all the variants of the matrix diagonals for the presence of sequences of balls.

Is it possible to modify this code for a mirror pass?

Answer 1

My decision:

for (int k = size; k >= -size; k--)
{
  for (int j = 0; j < size - k; j++)
  {
    int i = k + j;
    if (i < size && j < size && i >= 0 && j >= 0)
    {
      diagonal += arr2[j, i] + " ";
    }
  }

  Console.WriteLine(diagonal);
  diagonal = "";
}

Working code