Looking for an more efficient way to create a 4 directional linked-list - linked-list

Question

I am trying to create a method that will link all Cell objects set up in a 2D array named CellGrid[,]
My question is: Since most of the code in SetDirection() is so similar, it seem there is a better way to achieve my goal.
(Side note: This is functional but the execution feels "off" )
private void SetDirection()
{
int x = 0, y = 0;
for ( int i = 0 ; i < Size * (Size - 1);)//setting all UP pointers
{
if ( i == 0 ) { x = 0; y = 1;}//initial setup
for ( x = 0 ; x < Size ; x++ )
{
CellGrid[x,y].SetPointer(CellGrid[x,y-1] , Direction.Up );
i++;
}
y++;
}
for ( int i = 0 ; i < Size * (Size - 1);) //setting all DOWN pointers
{
if ( i == 0 ) { x = 0; y = 0;}//initial setup
for ( x = 0 ; x < Size ; x++ )
{
CellGrid[x,y].SetPointer(CellGrid[x,y+1], Direction.Down);
i++;
}
y++;
}
for ( int i = 0 ; i < Size * (Size - 1);)//setting all LEFT pointers
{
if ( i == 0 ) { x = 1; y = 0;}//initial setup
for ( y = 0 ; y < Size ; y++ )
{
CellGrid[x, y].SetPointer( CellGrid[x-1,y], Direction.Left);
i++;
}
x++;
}
for ( int i = 0 ; i < Size * (Size - 1);) //setting all RIGHT pointers
{
if ( i == 0 ) { x = 0; y = 0;}//initial setup
for ( y = 0 ; y < Size ; y++ )
{
CellGrid[x, y].SetPointer( CellGrid[x+1,y], Direction.Right);
i++;
}
x++;
}
}
public void SetPointer( Cell cellRef ,GridBuilder.Direction dir)
{
switch ( dir )
{
case GridBuilder.Direction.Up:
this.Up = cellRef;
break;
case GridBuilder.Direction.Down:
this.Down = cellRef;
break;
case GridBuilder.Direction.Left:
this.Left = cellRef;
break;
case GridBuilder.Direction.Right:
this.Right = cellRef;
break;
}
}

Answer 1

You can indeed use one set of loops to make the links in all four directions. This is based on two ideas:
When setting a link, immediately set the link in the opposite direction between the same two cells.
When setting a link, immediately set the link between the two cells that are located in the mirrored positions -- mirrored by the main diagonal (x <--> y).
private void SetDirection() {
for (int i = 1; i < Size; i++) {
for (int j = 0; j < Size; j++) {
CellGrid[i, j].SetPointer(CellGrid[i-1, j], Direction.Left);
CellGrid[i-1, j].SetPointer(CellGrid[i, j], Direction.Right);
CellGrid[j, i].SetPointer(CellGrid[j, i-1], Direction.Up);
CellGrid[j, i-1].SetPointer(CellGrid[j, i], Direction.Down);
}
}
}