Algorithm for traversing all lines in the n×n grid? - algorithm

Question

Use a two-dimensional array to represent a nxn grid.
var grid = new int[n,n];
Note that there are two more diagonal lines.

Answer 1

If i will solve this problem. I will make so.
Create extension method for Int[] (So, you can create your own class. But it's another way. I want to show light waight solution)
public static class IntAsMatrixExtensions {
public const int MatrixColumsCount = 3;
public static int At(this int[] matrix, int i, int j)
{
return matrix[i * MatrixColumsCount + j];
}
public static int[] Create()
{
var grid = new int[MatrixColumsCount*MatrixColumsCount] {
1,2,3,
4,5,6,
7,8,9
};
return grid;
}
}
Then first you should print matrix:
for(int i = 0; i < IntAsMatrixExtensions.MatrixColumsCount; i++)
{
for(int j = 0; j < IntAsMatrixExtensions.MatrixColumsCount; j++)
{
Console.Write(grid.At(i, j));
}
Console.WriteLine();
}
Then print transponated matrix:
for(int i = 0; i < IntAsMatrixExtensions.MatrixColumsCount; i++)
{
for(int j = 0; j < IntAsMatrixExtensions.MatrixColumsCount; j++)
{
Console.Write(grid.At(j, i)); //!!! i and j is swithed
}
Console.WriteLine();
}
Then print diag:
//Print diag
for(int i = 0; i < IntAsMatrixExtensions.MatrixColumsCount; i++)
{
Console.Write(grid.At(i, i)); //!!! i and j is swithed
}
Then print inverse diag:
for(int i = 0; i < IntAsMatrixExtensions.MatrixColumsCount; i++)
{
Console.Write(grid.At(i, IntAsMatrixExtensions.MatrixColumsCount - i - 1)); //!!! i and j is swithed
}
Here is example on fiddle https://dotnetfiddle.net/pyX31r