/// <summary>
/// Determines if the end is in the eastern vision of the walker and if so, sends the walker directly in that direction.
/// </summary>
/// <param name="walker">The walker.</param>
/// <returns>
/// A boolean value if the end is in the vicinity and also the walker with updated values.
/// </returns>
private bool is_eastfinish(MazeWalker walker)
{
bool is_finish = false;
int y = walker.Y;
int x = walker.X;
if (y < 0 || x < 0 || y >= m_maze_to_solve.Count)
{
return(false);
}
List <string> pixel_row = m_maze_to_solve[y];
if (x >= pixel_row.Count)
{
return(false);
}
while (pixel_row[x] != "1")
{
if (x >= pixel_row.Count)
{
break;
}
if (pixel_row[x] == "E")
{
is_finish = true;
break;
}
else
{
x++;
}
}
if (is_finish)
{
//finish the job
x = walker.X;
walker.Dir = Direction.East;
while (pixel_row[x] != "1" && pixel_row[x] != "E")
{
if (x >= pixel_row.Count)
{
break;
}
pixel_row[x] = "G";
x++;
walker.X = walker.X + 1;
MazeParser.color(m_maze_to_solve, walker);
}
}
return(is_finish);
}
/// <summary>
/// Determines if the end is in the southern vision of the walker and if so, sends the walker directly in that direction.
/// </summary>
/// <param name="walker">The walker.</param>
/// <returns>
/// A boolean value if the end is in the vicinity and also the walker with updated values.
/// </returns>
private bool is_southfinish(MazeWalker walker)
{
bool is_finish = false;
int y = walker.Y;
int x = walker.X;
if (y < 0 || x < 0 || y >= m_maze_to_solve.Count)
{
return(false);
}
for (; y < m_maze_to_solve.Count; y++)
{
List <string> pixel_row = m_maze_to_solve[y];
if (pixel_row[x] == "1")
{
break;
}
if (pixel_row[x] == "E")
{
is_finish = true;
break;
}
}
if (is_finish)
{
//finish the job
walker.Dir = Direction.South;
for (y = walker.Y; y < m_maze_to_solve.Count; y++)
{
List <string> pixel_row = m_maze_to_solve[y];
if (pixel_row[x] == "1")
{
break;
}
else if (pixel_row[x] == "E")
{
break;
}
else
{
pixel_row[x] = "X";
}
walker.Y = walker.Y + 1;
MazeParser.color(m_maze_to_solve, walker);
}
}
return(is_finish);
}
/// <summary>
/// Solves the given maze using the right-hand wall following method.
/// NOTE: this algorithm will not work for mazes that are not simply connected.
/// </summary>
/// <returns>
/// The parsed solution to the maze.
/// </returns>
private List <List <string> > solve_maze_RH()
{
bool pathFound = false;
MazeWalker walker = new MazeWalker();
walker = findstart(walker);
while (!pathFound)
{
//for each direction, test to see which directions are valid
//we always prioritize the current direction
//then the directions are prioritized according to the right-hand following method
if (walker.Dir == Direction.North)
{
bool move_success = false;
if (is_northvalid(walker.X, walker.Y))
{
move_success = walker.move_north(m_maze_to_solve);
}
else if (is_eastvalid(walker.X, walker.Y))
{
move_success = walker.move_east(m_maze_to_solve);
}
else if (is_westvalid(walker.X, walker.Y))
{
move_success = walker.move_west(m_maze_to_solve);
}
else
{
//turning back
move_success = walker.move_south(m_maze_to_solve);
}
if (!move_success)
{
return(null); //something went wrong somewhere
}
else
{
walker = turncorner(walker, walker.Dir);
}
}
else if (walker.Dir == Direction.South)
{
bool move_success = false;
if (is_southvalid(walker.X, walker.Y))
{
move_success = walker.move_south(m_maze_to_solve);
}
else if (is_westvalid(walker.X, walker.Y))
{
move_success = walker.move_west(m_maze_to_solve);
}
else if (is_eastvalid(walker.X, walker.Y))
{
move_success = walker.move_east(m_maze_to_solve);
}
else
{
//turn around
move_success = walker.move_north(m_maze_to_solve);
}
if (!move_success)
{
return(null);
}
else
{
walker = turncorner(walker, walker.Dir);
}
}
else if (walker.Dir == Direction.East)
{
bool move_success = false;
if (is_eastvalid(walker.X, walker.Y))
{
move_success = walker.move_east(m_maze_to_solve);
}
else if (is_southvalid(walker.X, walker.Y))
{
move_success = walker.move_south(m_maze_to_solve);
}
else if (is_northvalid(walker.X, walker.Y))
{
move_success = walker.move_north(m_maze_to_solve);
}
else
{
//turn around
move_success = walker.move_west(m_maze_to_solve);
}
if (!move_success)
{
return(null);
}
else
{
walker = turncorner(walker, walker.Dir);
}
}
else if (walker.Dir == Direction.West)
{
bool move_success = false;
if (is_westvalid(walker.X, walker.Y))
{
move_success = walker.move_west(m_maze_to_solve);
}
else if (is_northvalid(walker.X, walker.Y))
{
move_success = walker.move_north(m_maze_to_solve);
}
else if (is_southvalid(walker.X, walker.Y))
{
move_success = walker.move_south(m_maze_to_solve);
}
else
{
//turn around
move_success = walker.move_east(m_maze_to_solve);
}
if (!move_success)
{
return(null);
}
else
{
walker = turncorner(walker, walker.Dir);
}
}
else
{
//this should never be executed, but in case something goes wrong here, we will arbitrarily place the walker into a direction
walker.Dir = Direction.North;
}
MazeParser.color(m_maze_to_solve, walker);
pathFound = is_finish(walker);
MazeParser.color(m_maze_to_solve, walker);
}//end while
//MazeParser.output_parse(m_maze_to_solve); //for debugging
return(m_maze_to_solve);
}
