/// <summary>Override; see base.</summary>
public override ConstraintResult Process(SolverState state)
{
if (state.LastPlacedCell == null)
{
return(null);
}
var unknowns = AffectedCells.Count(af => state[af] == null);
if (unknowns != 1)
{
return(null);
}
var unknown = AffectedCells.First(af => state[af] == null);
state.MarkImpossible(unknown, value => !IsValid(
state[AffectedCells[0]] ?? value,
state[AffectedCells[1]] ?? value,
state[AffectedCells[2]] ?? value,
state[AffectedCells[3]] ?? value,
state[AffectedCells[4]] ?? value,
state[AffectedCells[5]] ?? value
));
return(null);
}
/// <summary>Override; see base.</summary>
public override ConstraintResult Process(SolverState state)
{
if (state.LastPlacedCell == null)
{
return(null);
}
foreach (var parity in _parities)
{
var count = AffectedCells.Count(cell => state[cell] != null && state[cell].Value % 2 == parity);
if (count == AffectedCells.Length / 2)
{
foreach (var cell in AffectedCells)
{
if (state[cell] == null)
{
for (var v = state.MinValue; v <= state.MaxValue; v++)
{
if (v % 2 == parity)
{
state.MarkImpossible(cell, v);
}
}
}
}
}
}
return(null);
}
/// <summary>Override; see base.</summary>
public override ConstraintResult Process(SolverState state)
{
if (state.LastPlacedCell == null)
{
return(null);
}
var unknowns = AffectedCells.Count(af => state[af] == null);
if (unknowns == 1)
{
var unknown = AffectedCells.First(af => state[af] == null);
state.MarkImpossible(unknown, value => !IsValid(
state[AffectedCells[0]] ?? value,
state[AffectedCells[1]] ?? value,
state[AffectedCells[2]] ?? value,
state[AffectedCells[3]] ?? value
));
}
else if (unknowns == 2)
{
var unkn1 = AffectedCells.First(af => state[af] == null);
var unkn1Ix = AffectedCells.IndexOf(unkn1);
var unkn2 = AffectedCells.Last(af => state[af] == null);
var numValues = state.MaxValue - state.MinValue + 1;
var possibles = new bool[numValues * numValues];
for (var val1 = state.MinValue; val1 <= state.MaxValue; val1++)
{
for (var val2 = state.MinValue; val2 <= state.MaxValue; val2++)
{
possibles[(val1 - state.MinValue) + numValues * (val2 - state.MinValue)] = IsValid(
state[AffectedCells[0]] ?? (unkn1Ix == 0 ? val1 : val2),
state[AffectedCells[1]] ?? (unkn1Ix == 1 ? val1 : val2),
state[AffectedCells[2]] ?? (unkn1Ix == 2 ? val1 : val2),
state[AffectedCells[3]] ?? (unkn1Ix == 3 ? val1 : val2));
}
}
state.MarkImpossible(unkn1, value1 => Enumerable.Range(0, numValues).All(value2 => !possibles[(value1 - state.MinValue) + numValues * value2]));
state.MarkImpossible(unkn2, value2 => Enumerable.Range(0, numValues).All(value1 => !possibles[value1 + numValues * (value2 - state.MinValue)]));
}
return(null);
}