private List<int> GetEffectivePossibilities(List<CellState> cellStates, CellState cstate, List<Cell> cell)
{
cell.RemoveAll(x => x.Value != 0);
var possibilities_within_group = new List<int>();
foreach (var item in cell)
{
if (item.Column == cstate.Cell.Column && item.Row == cstate.Cell.Row)
continue;
var itemstate = cellStates
.Where(c => c.Cell.Row == item.Row && c.Cell.Column == item.Column)
.Single();
possibilities_within_group.AddRange(itemstate.Possibilities);
}
var effectivepossibilities = new List<int>();
foreach (var item in cstate.Possibilities)
{
if (!possibilities_within_group.Contains(item))
{
effectivepossibilities.Add(item);
}
}
return effectivepossibilities.Count == 1 ?
effectivepossibilities : cstate.Possibilities;
}
private List<CellState> GetCellState()
{
var cells = this.maze.GetEmptyCells();
var needtoUpdateCellState = cells.Count > 0;
List<CellState> cellStates = new List<CellState>();
while (needtoUpdateCellState)
{
needtoUpdateCellState = false;
var cstate = new List<CellState>();
foreach (var cell in (cells = cells.Where(x => x.Value == 0).ToList()))
{
var cs = new CellState()
{
Cell = cell,
Possibilities = GetPosibilities(cell),
};
if (needtoUpdateCellState = (cs.Possibilities.Count == 1))
{
cell.Value = cs.Possibilities.First();
if (needSteps)
{
Steps.Add(new StepInfo(
Step.SET,
cell.Row,
cell.Column,
cell.Value,
string.Format("Cell ({1},{2}) has only one possibility and that is {0}.", cell.Value, cell.Row, cell.Column)
));
}
break;
}
if (cs.Possibilities.Count == 0)
{
HandleCellStateError(cs);
cells = this.maze.GetEmptyCells();
needtoUpdateCellState = true;
break;
}
cstate.Add(cs);
}
cellStates = cstate;
}
return cellStates;
}
private void HandleCellStateError(CellState cs)
{
if (SpeculationOn)
HandleSpeculationError();
}
