public void Mark(DLX solver)
{
solver.Mark(C1).Mark(C2 + 65);
}
public void Mark(DLX solver)
{
// mark the cell as being used
solver.Mark((0 * 5 * 81) + (Board * 81) + (Block * 9) + (3 * R) + C);
// mark the column as containing n
solver.Mark((1 * 5 * 81) + Board * 81 + 27 * (Block % 3) + 9 * C + N);
// mark the row as containing n
solver.Mark((2 * 5 * 81) + Board * 81 + 27 * (Block / 3) + 9 * R + N);
// mark the block as containing n
solver.Mark((3 * 5 * 81) + 9 * (Board * 9 + Block) + N);
if ((Board == 0 && Block == 8) || (Board == 1 && Block == 6) || (Board == 3 && Block == 2) || (Board == 4 && Block == 0)) {
// also mark the middle board
int MiddleBlock = 8 - Block;
int MiddleBoard = 2;
// mark the column as containing n
solver.Mark((1 * 5 * 81) + MiddleBoard * 81 + 27 * (MiddleBlock % 3) + 9 * C + N);
// mark the row as containing n
solver.Mark((2 * 5 * 81) + MiddleBoard * 81 + 27 * (MiddleBlock / 3) + 9 * R + N);
}
}
public void Mark(DLX solver)
{
// add a row for this number in this row and column
int block = (R / 3) + 3 * (C / 3); // relying on truncation, of course
// mark the cell as being used
solver.Mark(0 * 81 + 9 * R + C);
// mark the column as containing n
solver.Mark(1 * 81 + 9 * C + N);
// mark the row as containing n
solver.Mark(2 * 81 + 9 * R + N);
// mark the block as containing n
solver.Mark(3 * 81 + 9 * block + N);
}
