private BoardState puzzleDiver(BoardState b, int maxThreshhold)
{
// Gone as far as possible in this dive
if (b.moves.Count + b.distance >= maxThreshhold || IsSolved(b.positions))
{
return b;
}
List<int> moves = GetMoves(b.positions, b.moveTo);
foreach (int m in moves)
{
if (buttonTimer.Enabled)
{
List<int> newMoves = AddMove(b.moves, m);
int[] newPositions = ApplyMove(b.positions, m);
int moveTo = GetMoveTo(b.positions);
BoardState result = puzzleDiver(new BoardState(newMoves, newPositions, moveTo, GetDistance(newPositions)), maxThreshhold);
if (IsSolved(result.positions))
{
return result;
}
}
}
return b;
}
private void solvePuzzle()
{
List<int> moves = new List<int>();
bool done = false;
int[] positions = GetPositions();
int maxThreshold = GetDistance(positions);
BoardState currentState = new BoardState(moves, positions, -1, GetDistance(positions));
while (buttonTimer.Enabled)
{
BoardState completedState = puzzleDiver(currentState, maxThreshold);
if (IsSolved(completedState.positions))
{
foreach (int m in completedState.moves)
{
for (int i = 0; i < pieces; i++)
{
Tile t = tiles[i];
if (t.Row * cols + t.Col == m)
{
t.Invoke(new MethodInvoker(delegate
{
MovePiece(t);
}));
Thread.Sleep(100);
break;
}
}
}
string message = "Puzzle optimally solved in " + completedState.moves.Count + " moves.";
MessageBox.Show(message, "Done");
buttonTimer.Stop();
solveButton.Text = "Solve";
done = true;
break;
}
maxThreshold++;
}
if (!done)
{
string message = "I can not solve this puzzle in less than " + timeLimit + " seconds.";
MessageBox.Show(message, "Failed");
}
}