// Make a partial representing the board after a given digit is filled
public Partial(Partial parent, int digit_position, int digit_added)
{
// Duplicate parent's data
solver = parent.solver;
shape = parent.shape;
board = (int [])parent.board.Clone();
cell_fill_order = (int [])parent.cell_fill_order.Clone();
cell_fill_order [parent.depth] = digit_position;
depth = parent.depth + 1;
pencilling_freedoms = (bool [, ])parent.pencilling_freedoms.Clone();
pencilling_freedom_counts = (int [])parent.pencilling_freedom_counts.Clone();
set_penned_in = (bool [, ])parent.set_penned_in.Clone();
// Make the necessary changes
board [digit_position] = digit_added + 1;
for (int i = 0; i < shape.groups_by_cell [digit_position].Length; i++)
{
for (int j = 0; j < shape.group_size; j++)
{
int p = shape.groups_by_cell [digit_position] [i];
int q = shape.cells_by_group [p, j];
if (pencilling_freedoms [q, digit_added])
{
pencilling_freedom_counts [q]--;
if (pencilling_freedom_counts [q] == 0 && board [q] == 0)
{
is_automatically_unsolvable = true;
}
}
pencilling_freedoms [q, digit_added] = false;
}
set_penned_in [i, digit_added] = true;
}
}
// Construct an initial Partial representing a starting puzzle
public Partial(int [] board, RecursiveSolver solver)
{
this.board = board;
this.solver = solver;
shape = solver.shape;
cell_fill_order = new int [shape.num_cells - board.Where(i => i > 0).Count()];
#region Pencilling freedoms
pencilling_freedoms = new bool [shape.num_cells, shape.group_size];
for (int i = 0; i < shape.num_cells; i++)
{
for (int j = 0; j < shape.group_size; j++)
{
pencilling_freedoms [i, j] = true;
}
}
for (int i = 0; i < shape.num_cells; i++)
{
if (board [i] == 0)
{
continue;
}
for (int j = 0; j < shape.groups_by_cell [i].Length; j++)
{
for (int k = 0; k < shape.group_size; k++)
{
int p = shape.cells_by_group [shape.groups_by_cell [i] [j], k];
pencilling_freedoms [p, board [i] - 1] = false;
}
}
}
#endregion
#region Pencilling Counts
pencilling_freedom_counts = new int [shape.num_cells];
for (int i = 0; i < shape.num_cells; i++)
{
for (int j = 0; j < shape.group_size; j++)
{
if (pencilling_freedoms [i, j])
{
pencilling_freedom_counts [i]++;
}
}
}
#endregion
#region Set freedoms
set_penned_in = new bool [shape.num_groups, shape.group_size];
for (int g = 0; g < shape.num_groups; g++)
{
for (int d = 0; d < shape.group_size; d++)
{
for (int p = 0; p < shape.group_size; p++)
{
if (board [shape.cells_by_group [g, p]] == d + 1)
{
set_penned_in [g, d] = true;
break;
}
}
}
}
#endregion
}