int Solver::Solve2(KociembaCube& cube)
{
int iteration = 1;
int result = NOT_FOUND;
// Establish initial cost estimate to goal state
threshold2 = Phase2Cost(
cube.CornerPermutation(),
cube.NonMiddleSliceEdgePermutation(),
cube.MiddleSliceEdgePermutation());
nodes2 = 1; // Count root node here
solutionLength2 = 0;
do
{
newThreshold2 = Huge; // Any cost will be less than this
// Perform the phase 2 recursive IDA* search
result = Search2(
cube.CornerPermutation(),
cube.NonMiddleSliceEdgePermutation(),
cube.MiddleSliceEdgePermutation(), 0);
// Establish a new threshold for a deeper search
threshold2 = newThreshold2;
// Count interative deepenings
iteration++;
} while (result == NOT_FOUND);
// cout << "Phase 2 nodes = " << nodes2 << endl;
return result;
}
int Solver::Solve2(KociembaCube& cube)
{
int iteration = 1;
int result = NOT_FOUND;
threshold2 = Phase2Cost(
cube.CornerPermutation(),
cube.NonMiddleSliceEdgePermutation(),
cube.MiddleSliceEdgePermutation());
nodes++;
nodes2 = 1;
solutionLength2 = 0;
do
{
newThreshold2 = Huge;
result = Search2(
cube.CornerPermutation(),
cube.NonMiddleSliceEdgePermutation(),
cube.MiddleSliceEdgePermutation(), 0);
threshold2 = newThreshold2;
iteration++;
} while (result == NOT_FOUND);
Application->processEvents();
return result;
}
int Solver::Search2(
int cornerPermutation,
int nonMiddleSliceEdgePermutation,
int middleSliceEdgePermutation,
int depth)
{
int cost, totalCost;
int move;
int power, powerLimit;
int cornerPermutation2;
int nonMiddleSliceEdgePermutation2;
int middleSliceEdgePermutation2;
int result;
// Compute cost estimate to goal state
cost = Phase2Cost(
cornerPermutation,
nonMiddleSliceEdgePermutation,
middleSliceEdgePermutation); // h
if (cost == 0) // Solution found...
{
solutionLength2 = depth; // Save phase 2 solution length
if (solutionLength1 + solutionLength2 < minSolutionLength)
minSolutionLength = solutionLength1 + solutionLength2;
PrintSolution();
return FOUND;
}
// See if node should be expanded
totalCost = depth + cost; // g + h
if (totalCost <= threshold2) // Expand node
{
// No point in continuing to search for solutions of equal or greater
// length than the current best solution
if (solutionLength1 + depth >= minSolutionLength-1) return ABORT;
for (move = Cube::Move::R; move <= Cube::Move::B; move++)
{
if (Disallowed(move, solutionMoves2, depth)) continue;
cornerPermutation2 = cornerPermutation;
nonMiddleSliceEdgePermutation2 = nonMiddleSliceEdgePermutation;
middleSliceEdgePermutation2 = middleSliceEdgePermutation;
solutionMoves2[depth] = move;
powerLimit = 4;
if (move != Cube::Move::U && move != Cube::Move::D) powerLimit=2;
for (power = 1; power < powerLimit; power++)
{
cornerPermutation2 =
cornerPermutationMoveTable[cornerPermutation2][move];
nonMiddleSliceEdgePermutation2 =
nonMiddleSliceEdgePermutationMoveTable[nonMiddleSliceEdgePermutation2][move];
middleSliceEdgePermutation2 =
middleSliceEdgePermutationMoveTable[middleSliceEdgePermutation2][move];
solutionPowers2[depth] = power;
nodes2++;
// Apply the move
if (result = Search2(
cornerPermutation2,
nonMiddleSliceEdgePermutation2,
middleSliceEdgePermutation2, depth+1))
return result;
}
}
}
else // Maintain minimum cost exceeding threshold
{
if (totalCost < newThreshold2)
newThreshold2 = totalCost;
}
return NOT_FOUND;
}
int Solver::Search2(
int cornerPermutation,
int nonMiddleSliceEdgePermutation,
int middleSliceEdgePermutation,
int depth)
{
int cost, totalCost;
int move;
int power, powerLimit;
int cornerPermutation2;
int nonMiddleSliceEdgePermutation2;
int middleSliceEdgePermutation2;
int result;
cost = Phase2Cost(
cornerPermutation,
nonMiddleSliceEdgePermutation,
middleSliceEdgePermutation);
if (cost == 0)
{
solutionLength2 = depth;
if (solutionLength1 + solutionLength2 < minSolutionLength)
minSolutionLength = solutionLength1 + solutionLength2;
PrintSolution();
return FOUND;
}
if (cost < 2)
Window->ProgressStep(1);
totalCost = depth + cost;
if (totalCost <= threshold2)
{
if (solutionLength1 + depth >= minSolutionLength-1) return ABORT;
for (move = Cube::R; move <= Cube::B; move++)
{
if (Disallowed(move, solutionMoves2, depth)) continue;
cornerPermutation2 = cornerPermutation;
nonMiddleSliceEdgePermutation2 = nonMiddleSliceEdgePermutation;
middleSliceEdgePermutation2 = middleSliceEdgePermutation;
solutionMoves2[depth] = move;
powerLimit = 4;
if (move != Cube::U && move != Cube::D) powerLimit=2;
for (power = 1; power < powerLimit; power++)
{
cornerPermutation2 =
cornerPermutationMoveTable
[cornerPermutation2][move];
nonMiddleSliceEdgePermutation2 =
nonMiddleSliceEdgePermutationMoveTable
[nonMiddleSliceEdgePermutation2][move];
middleSliceEdgePermutation2 =
middleSliceEdgePermutationMoveTable
[middleSliceEdgePermutation2][move];
solutionPowers2[depth] = power;
nodes2++;
if ((result = Search2(
cornerPermutation2,
nonMiddleSliceEdgePermutation2,
middleSliceEdgePermutation2, depth+1)))
return result;
}
}
}
else
{
if (totalCost < newThreshold2)
newThreshold2 = totalCost;
}
return NOT_FOUND;
}
