public static int SolutionChanges(Level level, MoveList solution)
{
if (solution == null)
{
return -1;
}
Level tempLevel = new Level(level);
int changes = 0;
int lastBoxIndex = -1;
foreach (OperationDirectionPair pair in solution)
{
if (pair.Operation == Operation.Push)
{
int boxIndex = tempLevel.BoxIndex(tempLevel.SokobanCoordinate + pair.Direction);
if (boxIndex != lastBoxIndex)
{
changes++;
lastBoxIndex = boxIndex;
}
}
tempLevel.Move(pair);
}
return changes;
}
public static MoveList ShortenToFirstPush(Level level, MoveList moveList)
{
// Perform and count initial moves.
int initialMoves = 0;
foreach (OperationDirectionPair pair in moveList)
{
if (pair.Operation == Operation.Push)
{
break;
}
level.Move(pair);
initialMoves++;
}
// Make a copy of the move list and shorten it.
MoveList finalMoveList = new MoveList(moveList);
finalMoveList.RemoveRange(0, initialMoves);
return finalMoveList;
}
public static int MinimumBoxMoves(Level level, MoveList solution)
{
if (solution == null)
{
return -1;
}
int boxes = level.Boxes;
if (boxes == 0)
{
return 0;
}
int[] boxMoves = new int[boxes];
Level tempLevel = new Level(level);
foreach (OperationDirectionPair pair in solution)
{
if (pair.Operation == Operation.Push)
{
boxMoves[tempLevel.BoxIndex(tempLevel.SokobanCoordinate + pair.Direction)]++;
}
tempLevel.Move(pair);
}
int min = int.MaxValue;
foreach (int moves in boxMoves)
{
min = Math.Min(min, moves);
}
return min;
}
public static bool IsSolutionCompatible(Level level, MoveList solution)
{
Level tempLevel = new Level(level);
foreach (OperationDirectionPair pair in solution)
{
if (!tempLevel.Move(pair.Operation, pair.Direction))
{
if (pair.Operation != Operation.Move || !tempLevel.Move(Operation.Push, pair.Direction))
{
return false;
}
}
}
return true;
}
public static Array2D<int> GetTraversalMap(Level level, MoveList solution)
{
// Create a traversal map counting the number of times
// each square is occupied during the course of the solution,
// initialized to zero.
Array2D<int> traversalMap = new Array2D<int>(level.Height, level.Width);
Level tempLevel = new Level(level);
// Count the starting positions as one traversal.
traversalMap[tempLevel.SokobanCoordinate]++;
foreach (Coordinate2D coord in tempLevel.BoxCoordinates)
{
traversalMap[coord]++;
}
// Count all sokoban positions and box movements in the solution.
foreach (OperationDirectionPair pair in solution)
{
if (pair.Operation == Operation.Push)
{
traversalMap[tempLevel.SokobanCoordinate + 2 * pair.Direction]++;
}
tempLevel.Move(pair);
traversalMap[tempLevel.SokobanCoordinate]++;
}
return traversalMap;
}
protected void CollectSolution(Node leaf)
{
foundSolution = true;
// Don't bother if we're not collection solutions.
if (!collectSolutions)
{
return;
}
// Prepare to construct the solution.
MoveList solution = new MoveList();
Level tempLevel = new Level(originalLevel);
tempLevel.Validate = validate;
PathFinder tempFinder = PathFinder.CreateInstance(tempLevel, true);
// Iterate over the nodes from the root to the leaf.
int previousPushes = 0;
#if false
List<Node> nodeList = FindParents(root, leaf);
#else
List<Node> nodeList = new List<Node>();
for (int i = 0; i < current.ParentIndex; i++)
{
nodeList.Add(current.Parents[i]);
}
nodeList.Add(leaf);
#endif
foreach (Node node in nodeList)
{
// Check whether we need to move the sokoban.
if (node.Coordinate != tempLevel.SokobanCoordinate)
{
// Move the sokoban to the box.
solution.AddRange(tempFinder.FindAndGetPath(node.Coordinate));
tempLevel.MoveSokoban(node.Coordinate);
}
// Check whether we need to push a box.
int consecutivePushes = node.Pushes - previousPushes;
if (consecutivePushes != 0)
{
// Push the box one or more times.
OperationDirectionPair push = new OperationDirectionPair(Levels.Operation.Push, node.Direction);
for (int j = 0; j < consecutivePushes; j++)
{
solution.Add(push);
tempLevel.Move(push);
}
previousPushes = node.Pushes;
}
}
// Validate the solution.
if (!tempLevel.IsComplete)
{
throw Abort("constructed move list does not solve level");
}
if (optimizeMoves && solution.Count != leaf.Moves)
{
throw Abort("constructed move list does not match leaf tree in moves");
}
if (LevelUtils.SolutionPushes(solution) != leaf.Pushes)
{
throw Abort("constructed move list does not match leaf tree in pushes");
}
// Add the solution.
solutions.Add(solution);
int moves = solution.Count;
int pushes = LevelUtils.SolutionPushes(solution);
moveLimit = Math.Min(moveLimit, moves);
pushLimit = Math.Min(pushLimit, pushes);
#if DEBUG
if (verbose)
{
Log.DebugPrint(" found solution: {0}/{1}", moves, pushes);
}
#endif
}
