private void SearchPhase2(int cp, int equatorPermutation, int udEdgeOrder, int depth, int remainingMoves, int phase1Length)
{
if (IsTerminated.Value)
{
return;
}
if (remainingMoves == 0 && equatorPermutation == 0) //check if solved
{
Alg solution = Alg.FromEnumerable(_currentPhase1Solution.Take(phase1Length).Concat(_currentPhase2Solution.Take(depth)).Cast <Move>());
for (int i = 0; i < _rotation; i++)
{
solution = solution.Rotate(Rotation.y3).Rotate(Rotation.x3);
}
if (_inversed)
{
solution = solution.Inverse();
}
lock (_lockObject)
{
if (solution.Length < _shortestSolutionLength.Value)
{
_shortestSolutionIndex.Value = _solutions.Count;
_shortestSolutionLength.Value = solution.Length;
}
_solutions.Add(solution);
}
if (solution.Length <= _returnLength)
{
IsTerminated.Value = true;
}
return;
}
//increase depth
foreach (int move in TwoPhaseConstants.Phase2Moves)
{
//prevent two consecutive moves on the same face or two
//consecutive moves on the same axis in the wrong order
if (depth == 0)
{
if (phase1Length > 0)
{
int relation = move / 3 - _currentPhase1Solution[phase1Length - 1] / 3;
if (relation == SameFace || relation == SameAxisInWrongOrder)
{
continue;
}
}
}
else
{
int relation = move / 3 - _currentPhase2Solution[depth - 1] / 3;
if (relation == SameFace || relation == SameAxisInWrongOrder)
{
continue;
}
}
int newCp = TableController.CornerPermutationMoveTable[cp, move];
int newEquatorPermutation = TableController.EquatorPermutationMoveTable[equatorPermutation, move];
int newUdEdgePermutation = TableController.UdEdgeOrderMoveTable[udEdgeOrder, MoveTables.Phase1IndexToPhase2Index[move]];
//prune
int cornerUdPruningIndex = PruningTables.GetPhase2CornerUdPruningIndex(newUdEdgePermutation, newCp);
int cornerUdPruningValue = TableController.Phase2CornerUdPruningTable[cornerUdPruningIndex];
int cornerEquatorPruningIndex = Coordinates.NumEquatorOrders * newCp + newEquatorPermutation;
int cornerEquatorPruningValue = TableController.Phase2CornerEquatorPruningTable[cornerEquatorPruningIndex];
if (Math.Max(cornerUdPruningValue, cornerEquatorPruningValue) > remainingMoves - 1)
{
continue;
}
_currentPhase2Solution[depth] = move;
SearchPhase2(newCp, newEquatorPermutation, newUdEdgePermutation, depth + 1, remainingMoves - 1, phase1Length);
}
}
private void SearchPhase1(int eo, int co, int equator, int depth, int remainingMoves, int previousPruningValue)
{
if (IsTerminated.Value)
{
return;
}
if (remainingMoves == 0) //check if solved
{
lock (_lockObject) //manage timeout
if (_timePassed.Elapsed > _timeout && (_requiredLength < 0 || (_solutions.Count > 0 && _shortestSolutionLength.Value <= _requiredLength)))
{
IsTerminated.Value = true;
}
int cp = _cp;
int uEdges = _uEdges;
int dEdges = _dEdges;
int equatorPermutation = equator;
//TEST improvement
for (int moveIndex = 0; moveIndex < depth; moveIndex++)
{
int move = _currentPhase1Solution[moveIndex];
cp = TableController.CornerPermutationMoveTable[cp, move];
}
int cornerEquatorPruningIndex = Coordinates.NumEquatorOrders * cp + equator;
int cornerEquatorPruningValue = TableController.Phase2CornerEquatorPruningTable[cornerEquatorPruningIndex];
if (cornerEquatorPruningValue > MaxPhase2Length)
{
return;
}
for (int moveIndex = 0; moveIndex < depth; moveIndex++)
{
int move = _currentPhase1Solution[moveIndex];
uEdges = TableController.UEdgePermutationMoveTable[uEdges, move];
dEdges = TableController.DEdgePermutationMoveTable[dEdges, move];
}
int udEdgeOrder = Coordinates.CombineUEdgePermutationAndDEdgeOrder(uEdges, dEdges % Coordinates.NumDEdgeOrders);
//prune
int cornerUdPruningIndex = PruningTables.GetPhase2CornerUdPruningIndex(udEdgeOrder, cp);
int minMoves = TableController.Phase2CornerUdPruningTable[cornerUdPruningIndex];
int maxMoves = Math.Min(_shortestSolutionLength.Value - depth - 1, MaxPhase2Length);
for (int length = minMoves; length <= maxMoves; length++)
{
SearchPhase2(cp, equatorPermutation, udEdgeOrder, depth: 0, remainingMoves: length, phase1Length: depth);
}
return;
}
//increase depth
for (int move = 0; move < NumMoves; move++)
{
//If the cube is already in the subgroup H and there are less
//than 5 moves left it is only possible to stay in the subgroup
//if exclusivly phase 2 moves are used, which means that this
//solution can also be generated in phase 2.
if (previousPruningValue == 0 && remainingMoves < 5 && !TwoPhaseConstants.Phase2Moves.Contains((Move)move))
{
continue;
}
//prevent two consecutive moves on the same face or two
//consecutive moves on the same axis in the wrong order
if (depth > 0)
{
int relation = move / 3 - _currentPhase1Solution[depth - 1] / 3;
if (relation == SameFace || relation == SameAxisInWrongOrder)
{
continue;
}
}
int newEo = TableController.EdgeOrientationMoveTable[eo, move];
int newCo = TableController.CornerOrientationMoveTable[co, move];
int newEquator = TableController.EquatorPermutationMoveTable[equator, move];
//prune
int pruningCoord = PruningTables.GetPhase1PruningIndex(newCo, newEo, newEquator / Coordinates.NumEquatorOrders);
int pruningValue = TableController.Phase1PruningTable[pruningCoord];
if (pruningValue > remainingMoves - 1)
{
continue;
}
_currentPhase1Solution[depth] = move;
SearchPhase1(newEo, newCo, newEquator, depth + 1, remainingMoves - 1, pruningValue);
}
}