public static int[,] FillMatrix(int n)
{
int[,] matrix = new int[n, n];
Position position = new Position(0, 0);
int value = 1, currentDirectionX = 1, currentDirectionY = 1;
while (value <= n * n)
{
matrix[position.Row, position.Col] = value;
if (!CheckIfFreeCellExists(matrix, position.Row, position.Col))
{
value++;
if (value > n * n)
{
break;
}
FindEmptyCellCoordinates(matrix, position);
matrix[position.Row, position.Col] = value;
currentDirectionX = 1;
currentDirectionY = 1;
}
while (CheckIfPositionAfterChangeIsOutOfMatrix(n, position.Row, currentDirectionX) ||
CheckIfPositionAfterChangeIsOutOfMatrix(n, position.Col, currentDirectionY) ||
matrix[position.Row + currentDirectionX, position.Col + currentDirectionY] != 0)
{
ChangeDirection(ref currentDirectionX, ref currentDirectionY);
}
position.Update(currentDirectionX, currentDirectionY);
value++;
}
return matrix;
}
private static void FindEmptyCellCoordinates(int[,] matrix, Position position)
{
position.Row = 0;
position.Col = 0;
for (int row = 0; row < matrix.GetLength(0); row++)
{
for (int col = 0; col < matrix.GetLength(1); col++)
{
// if the cell is free
if (matrix[row, col] == 0)
{
position.Row = row;
position.Col = col;
return;
}
}
}
}