// Solve the maze using a depth-first traversal algorithm
public void SolveMaze()
{
//System.Random rand2 = new System.Random((int)DateTime.Now.Ticks);
if (!gen) return;
// Check if the maze has been solved
if (solutionPath != null) solutionPath = null;
Stack<Cell> PathStack = new Stack<Cell>();
int r, c;
Cell EndCell, CurrentCell, SelectedCell;
EndCell.row = endR;
EndCell.col = nC - 1;
EndCell.visited = false;
CurrentCell.row = startR;
CurrentCell.col = 0;
CurrentCell.visited = false;
visited[startR, 0] = true;
for (r = 0; r < nR; r++)
for (c = 0; c < nC; c++)
visited[r, c] = false;
visited[startR, 0] = true;
int nvisited = 0; // for search performance measure
int visitedIndex;
Cell[] T = new Cell[4];
r = CurrentCell.row;
c = CurrentCell.col;
while ((CurrentCell.row != EndCell.row) || (CurrentCell.col != EndCell.col))
{
visitedIndex = 0;
for (int i = 0; i < 4; i++)
{
T[i].visited = true;
}
//check north cell
if (r != (nR - 1))
{
if ((!northWall[r, c]) && (!visited[r + 1, c]))
{
T[visitedIndex].row = r + 1;
T[visitedIndex].col = c;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
if (c != (nC - 1))
{
//check east cell
if ((!eastWall[r, c]) && (!visited[r, c + 1]))
{
T[visitedIndex].row = r;
T[visitedIndex].col = c + 1;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
if (c != 0)
{
//check west cell
if ((!eastWall[r, c - 1]) && (!visited[r, c - 1]))
{
T[visitedIndex].row = r;
T[visitedIndex].col = c - 1;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
if (r != 0)
{
//check south cell
if ((!northWall[r - 1, c]) && (!visited[r - 1, c]))
{
T[visitedIndex].row = r - 1;
T[visitedIndex].col = c;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
if (visitedIndex > 0)
{
//If there is at least one cell unvisited, randomly select one
SelectedCell = T[rand.Next() % visitedIndex];
//push the current cell onto the stack
PathStack.Push(CurrentCell);
//choose the selected cell as current cell
CurrentCell = SelectedCell;
r = CurrentCell.row;
c = CurrentCell.col;
CurrentCell.visited = true;
visited[r, c] = true;
nvisited++;
}
else
{
// If there is no cell unvisited, pop cell from the stack;
// The poped cell is not part of the solution path.
CurrentCell = PathStack.Pop();
r = CurrentCell.row;
c = CurrentCell.col;
CurrentCell.visited = true;
visited[r, c] = true;
nvisited++;
}
}
if (PathStack.Count > 0)
{
solutionPath = new Cell[PathStack.Count];
PathStack.CopyTo(solutionPath, 0); // Solution path is in reversed order
}
Debug.Log("SolotuonPath : Number of nodes visited = " + nvisited.ToString());
Debug.Log("SolutionPath : Path length = " + solutionPath.Length.ToString());
}
// Generate a maze using a depth-first search algorithm with more horizontal influence
public void GenerateMaze2()
{
//System.Random rand2 = new System.Random((int)DateTime.Now.Ticks);
Stack<Cell> CellStack = new Stack<Cell>();
int TotalCells = nR * nC;
Cell CurrentCell, SelectedCell;
int VisitedCells;
// Randomly select one cell as current cell
//setBarrierCell();
int r = rand.Next() % nR;
int c = rand.Next() % nC;
CurrentCell.row = r;
CurrentCell.col = c;
CurrentCell.visited = false;
visited[r, c] = true;
VisitedCells = 1;
int visitedIndex;
Cell[] T = new Cell[4];
bool isEast = false;
int indexEast = 0;
bool isWest = false;
int indexWest = 0;
while (VisitedCells < TotalCells)
{
visitedIndex = 0;
isEast = false;
isWest = false;
for (int i = 0; i < 4; i++)
{
T[i].visited = true;
}
// Check north cell
if (r != (nR - 1))
{
if (!visited[r + 1, c])
{
T[visitedIndex].row = r + 1;
T[visitedIndex].col = c;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
// Check west cell
if (c != 0)
{
if (!visited[r, c - 1])
{
isWest = true;
indexWest = visitedIndex;
T[visitedIndex].row = r;
T[visitedIndex].col = c - 1;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
// Check south cell
if (r != 0)
{
if (!visited[r - 1, c])
{
T[visitedIndex].row = r - 1;
T[visitedIndex].col = c;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
// Check east cell
if (c != nC - 1)
{
if (!visited[r, c + 1])
{
isEast = true;
indexEast = visitedIndex;
T[visitedIndex].row = r;
T[visitedIndex].col = c + 1;
T[visitedIndex].visited = false;
visitedIndex++;
}
}
if (visitedIndex > 0)
{
// Select East or West unvisited cell first if there is any;
// otherwiese randomly select one
if (isWest)
SelectedCell = T[indexWest];
//else if (isEast)
// SelectedCell = T[indexEast];
else // If there is at least one cell unvisited, randomly select one.
SelectedCell = T[rand.Next() % visitedIndex];
// Knock down the wall between these two cells.
// Note: (r,c) is the CurrentCell.
if ((SelectedCell.row == (r + 1)) && (SelectedCell.col == c))
northWall[r, c] = false;
if ((SelectedCell.row == r) && (SelectedCell.col == (c - 1)))
eastWall[r, c - 1] = false;
if ((SelectedCell.row == (r - 1)) && (SelectedCell.col == c))
northWall[r - 1, c] = false;
if ((SelectedCell.row == r) && (SelectedCell.col == (c + 1)))
eastWall[r, c] = false;
CellStack.Push(CurrentCell);
// Choose the selected cell as the current cell
CurrentCell = SelectedCell;
r = CurrentCell.row;
c = CurrentCell.col;
visited[r, c] = true;
VisitedCells++;
}
else
{
//If there is no cell unvisited, pop cell from the stack
CurrentCell = CellStack.Pop();
r = CurrentCell.row;
c = CurrentCell.col;
visited[r, c] = true;
}
}
CellStack.Clear();
// Randomly select the start and end cell
startR = rand.Next() % nR;
endR = rand.Next() % (nR - 1) + 1;
//endR = rand.Next() % nR;
eastWall[endR, (nC - 1)] = false;
//removeWalls(30);
// Set the gen flag and clear the solution path
gen = true;
solutionPath = null;
path = null;
}
