Modify the Maze class so that it prints out the path of the final solutions as i
ID: 3560364 • Letter: M
Question
Modify the Maze class so that it prints out the path of the final solutions as it is discovered without storing it.
public class Maze
{
private final int TRIED = 3;
private final int PATH = 7;
private int[][] grid = { {1,1,1,0,1,1,0,0,0,1,1,1,1},
{1,0,1,1,1,0,1,1,1,1,0,0,1},
{0,0,0,0,1,0,1,0,1,0,1,0,0},
{1,1,1,0,1,1,1,0,1,0,1,1,1},
{1,0,1,0,0,0,0,1,1,1,0,0,1},
{1,0,1,1,1,1,1,1,0,1,1,1,1},
{1,0,0,0,0,0,0,0,0,0,0,0,0},
{1,1,1,1,1,1,1,1,1,1,1,1,1} };
//-----------------------------------------------------------------
// Attempts to recursively traverse the maze. Inserts special
// characters indicating locations that have been tried and that
// eventually become part of the solution.
//-----------------------------------------------------------------
public boolean traverse(int row, int column)
{
boolean done = false;
if (valid(row, column))
{
grid[row][column] = TRIED; // this cell has been tried
if (row == grid.length-1 && column == grid[0].length-1)
done = true; // the maze is solved
else
{
done = traverse(row+1, column); // down
if (!done)
done = traverse(row, column+1); // right
if (!done)
done = traverse(row-1, column); // up
if (!done)
done = traverse(row, column-1); // left
}
if (done) // this location is part of the final path
grid[row][column] = PATH;
}
return done;
}
//-----------------------------------------------------------------
// Determines if a specific location is valid.
//-----------------------------------------------------------------
private boolean valid(int row, int column)
{
boolean result = false;
// check if cell is in the bounds of the matrix
if (row >= 0 && row < grid.length &&
column >= 0 && column < grid[row].length)
// check if cell is not blocked and not previously tried
if (grid[row][column] == 1)
result = true;
return result;
}
//-----------------------------------------------------------------
// Returns the maze as a string.
//-----------------------------------------------------------------
public String toString()
{
String result = " ";
for (int row=0; row < grid.length; row++)
{
for (int column=0; column < grid[row].length; column++)
result += grid[row][column] + "";
result += " ";
}
return result;
}
}
//********************************************************************
// MazeSearch.java Author: Lewis/Loftus
//
// Demonstrates recursion.
//********************************************************************
public class MazeSearch
{
//-----------------------------------------------------------------
// Creates a new maze, prints its original form, attempts to
// solve it, and prints out its final form.
//-----------------------------------------------------------------
public static void main(String[] args)
{
Maze labyrinth = new Maze();
System.out.println(labyrinth);
if (labyrinth.traverse(0, 0))
System.out.println("The maze was successfully traversed!");
else
System.out.println("There is no possible path.");
System.out.println(labyrinth);
}
}
Explanation / Answer
class Maze
{
private final int TRIED = 3;
private final int PATH = 7;
private int[][] grid = { {1,1,1,0,1,1,0,0,0,1,1,1,1},
{1,0,1,1,1,0,1,1,1,1,0,0,1},
{0,0,0,0,1,0,1,0,1,0,1,0,0},
{1,1,1,0,1,1,1,0,1,0,1,1,1},
{1,0,1,0,0,0,0,1,1,1,0,0,1},
{1,0,1,1,1,1,1,1,0,1,1,1,1},
{1,0,0,0,0,0,0,0,0,0,0,0,0},
{1,1,1,1,1,1,1,1,1,1,1,1,1} };
//-----------------------------------------------------------------
// Attempts to recursively traverse the maze. Inserts special
// characters indicating locations that have been tried and that
// eventually become part of the solution.
//-----------------------------------------------------------------
public boolean traverse(int row, int column)
{
boolean done = false;
if (valid(row, column))
{
grid[row][column] = TRIED; // this cell has been tried
if (row == grid.length-1 && column == grid[0].length-1)
done = true; // the maze is solved
else
{
done = traverse(row+1, column); // down
if (!done)
done = traverse(row, column+1); // right
if (!done)
done = traverse(row-1, column); // up
if (!done)
done = traverse(row, column-1); // left
}
if (done) // this location is part of the final path
grid[row][column] = PATH;
}
return done;
}
//-----------------------------------------------------------------
// Determines if a specific location is valid.
//-----------------------------------------------------------------
private boolean valid(int row, int column)
{
boolean result = false;
// check if cell is in the bounds of the matrix
if (row >= 0 && row < grid.length &&
column >= 0 && column < grid[row].length)
// check if cell is not blocked and not previously tried
if (grid[row][column] == 1)
result = true;
return result;
}
//-----------------------------------------------------------------
// Returns the maze as a string.
//-----------------------------------------------------------------
public String toString()
{
String result = " ";
for (int row=0; row < grid.length; row++)
{
for (int column=0; column < grid[row].length; column++)
result += grid[row][column] + "";
result += " ";
}
return result;
}
}
//********************************************************************
// MazeSearch.java Author: Lewis/Loftus
//
// Demonstrates recursion.
//********************************************************************
public class MazeSearch
{
//-----------------------------------------------------------------
// Creates a new maze, prints its original form, attempts to
// solve it, and prints out its final form.
//-----------------------------------------------------------------
public static void main(String[] args)
{
Maze labyrinth = new Maze();
System.out.println(labyrinth);
if (labyrinth.traverse(0, 0))
System.out.println("The maze was successfully traversed!");
else
System.out.println("There is no possible path.");
System.out.println(labyrinth);
}
}
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.