protected bool IsTerminalWithoutMoves(ref MoveState state, Node node)
{
// Update current hash key for node.
#if USE_INCREMENTAL_PATH_FINDER
state.Find(ref current);
#else
pathFinder.Find(current.SokobanRow, current.SokobanColumn);
#endif
#if USE_INCREMENTAL_HASH_KEY
Coordinate2D proxySokobanCoord = pathFinder.GetFirstAccessibleCoordinate();
current.HashKey ^= HashKey.GetSokobanHashKey(proxySokobanCoord.Row, proxySokobanCoord.Column);
#else
current.HashKey = GetSlowHashKey();
#endif
#if DEBUG
ValidateHashKey(node);
#endif
// Look up the current hash key in the transposition table.
Node other;
if (transpositionTable.TryGetValue(current.HashKey, out other))
{
duplicates++;
// Choose which node to pursue.
if (Node.IsEmpty(other) || other.Pushes <= node.Pushes)
{
// The other node is deadlocked or as good as this one.
return true;
}
// This node is better than the other one, which is not deadlocked.
transpositionTable[current.HashKey] = node;
node.InTable = true;
other.InTable = false;
if (other.Dormant)
{
nodes.Release(other);
}
else
{
other.Terminal = true;
}
#if DEBUG
ValidateNotDeadlocked();
#endif
return false;
}
if (deadlockFinder.IsDeadlocked(current.SokobanRow, current.SokobanColumn))
{
transpositionTable.Add(current.HashKey, Node.Empty);
return true;
}
transpositionTable.Add(current.HashKey, node);
node.InTable = true;
return false;
}
protected bool IsTerminalWithMoves(ref MoveState state, Node node)
{
// Update current hash key for node.
#if USE_INCREMENTAL_HASH_KEY
current.HashKey ^= HashKey.GetSokobanHashKey(current.SokobanRow, current.SokobanColumn);
#else
current.HashKey = GetSlowHashKey();
#endif
#if DEBUG
ValidateHashKey(node);
#endif
// Look up the current hash key in the transposition table.
Node other;
if (transpositionTable.TryGetValue(current.HashKey, out other))
{
duplicates++;
// Choose which node to pursue.
if (optimizePushes)
{
if (Node.IsEmpty(other) || other.Pushes < node.Pushes ||
other.Pushes == node.Pushes && other.Moves <= node.Moves)
{
// The other node is deadlocked or as good as than this one.
return true;
}
}
else
{
if (Node.IsEmpty(other) || other.Moves <= node.Moves)
{
// The other node is deadlocked or as good as than this one.
return true;
}
}
// This node is better than the other one, which is not deadlocked.
transpositionTable[current.HashKey] = node;
node.InTable = true;
other.InTable = false;
if (other.Dormant)
{
nodes.Release(other);
}
else
{
other.Terminal = true;
}
// This is no longer a duplicate and not deadlocked, so run the finder.
#if USE_INCREMENTAL_PATH_FINDER
state.Find(ref current);
#else
pathFinder.Find(current.SokobanRow, current.SokobanColumn);
#endif
#if DEBUG
ValidateNotDeadlocked();
#endif
return false;
}
if (deadlockFinder.IsDeadlocked(current.SokobanRow, current.SokobanColumn))
{
transpositionTable.Add(current.HashKey, Node.Empty);
return true;
}
// This is a brand new position, so record it.
transpositionTable.Add(current.HashKey, node);
node.InTable = true;
// This is not a duplicate and not deadlocked, so run the finder.
#if USE_INCREMENTAL_PATH_FINDER
state.Find(ref current);
#else
pathFinder.Find(current.SokobanRow, current.SokobanColumn);
#endif
return false;
}