Java Question help needed In the program Fill the Add state

Java Question : help needed In the program \"Fill the Add statements Area\" here area. Sample Output in the picture

Consider a maze made up of a rectangular array of squares. The maze will contain a

character (either +, -, or |) to represent a blocked square, and to form the walls of the

maze. Mazes will have only one entrance at the Coordinate (0, 1), with only one exit in

the lower right hand corner of the maze.

Beginning at the entrance to the maze, find a path to the exit at the bottom right of the

maze. You may only move up, down, left, and right. Each square in the maze can be in

one of four states: clear (space), blocked (X), path (.), or visited (*). Initially, after the

maze has been read in from the file, each square will be either clear or blocked. If a

square lies on a successful path, mark it with a period. If you visit a square but it does

not lead to a successful path, mark it as visited with an asterisk.

This is the program for it

public class Coordinate {

public int x;

public int y;

public Coordinate( int x, int y ) {

this.x = x;

this.y = y;

}

public String toString() {

return \"(\" + this.x + \",\" + this.y + \")\";

}

@Override

public boolean equals( Object object ) {

if( object == null ) {

return false;

}

if( ! Coordinate.class.isAssignableFrom( object.getClass() )) {

return false;

}

final Coordinate other = (Coordinate) object;

return this.x == other.x && this.y == other.y;

}

}

import java.util.Vector;

public class Maze {

private char[][] maze;

private int height;

private int width;

/**

   * Create a new Maze of the specified height and width, initializing every

   * location as empty, with a \' \'.

   **/

public Maze( int width, int height ) {

      this.width = width;

      this.height = height;      

      this.maze = new char [this.width][this.height];

// ADD STATEMENTS HERE

}

/**

   * Mutator to allow us to set the specified Coordinate as blocked,

   * marking it with a \'X\'

   **/

public void setBlocked( Coordinate coord ) {

// ADD STATEMENTS HERE

  

}

/**

   * Mutator to allow us to set the specified Coordinate as having been visited,

   * marking it with a \'*\'

   **/

public void setVisited( Coordinate coord ) {

// ADD STATEMENTS HERE

}

/**

   * Mutator to allow us to set the specified Coordinate as part of the path solution,

   * marking it with a \'.\'

   **/

public void setPath( Coordinate coord ) {

// ADD STATEMENTS HERE

  

}

/**

   * Returns the character at the locatio specified by the Coordinate

   **/

public char at( Coordinate coord ) {

// ADD STATEMENTS HERE

}

/**

   * Returns a Coordinate array containing all Coordinates that are clear around

   * the specified coordinate.

   **/

public Coordinate[] clearAround( Coordinate coord ) {

Vector vector = new Vector();

// ADD STATEMENTS HERE

// Look at each of the locations around the specified Coordinate, and add it

// to the vector if it is clear (i.e. a space)

return vector.toArray( new Coordinate[0] );

}

/**

   * Returns a Coordinate that provides the entrance location in this maze.

   **/

public Coordinate start() {

return new Coordinate( 0, 1 );

}

/**

   * Returns a Coordinate that provides the exit location from this maze.

   **/

public Coordinate end() {

// ADD STATEMENTS HERE

  

}

/**

   * The toString() method is responsible for creating a String representation

   * of the Maze. See the project specification for sample output. Note that

   * the String representation adds numbers across the top and side of the Maze

   * to show the Coordinates of each cell in the maze.

   **/

public String toString() {

StringBuilder buffer = new StringBuilder();

// ADD STATEMENTS HERE

// First, print out the column headings

// Next, print out each row in the maze - note the spaces between

// cells to facilitate reading. Each row should include its row number.

for(int x=0; x

for(int y=0; y

buffer.append(maze[x][y]);

buffer.append(\"\ \");

  

  

  

return buffer.toString();

}

}

package p2;

import java.io.FileNotFoundException;

public class MazeSolver {

private Maze maze;

private LinkedStack path;

public MazeSolver( Maze maze ) {

// ADD STATEMENTS HERE

}

public void solve() {

// ADD STATEMENTS HERE

// Add the starting Coordinate to the maze, and while the Stack has

// entries, and the top of the Stack is not the end, continue searching

// for the path

}

public static void main( String[] args ) throws FileNotFoundException {

MazeReader reader = new MazeReader( \"sampleMaze.txt\" );

Maze maze = reader.open();

MazeSolver solver = new MazeSolver( maze );

System.out.println( \"Before solving\" );

System.out.println( maze );

System.out.println( \"Start is \" + maze.start() );

System.out.println( \"End is \" + maze.end() );

solver.solve();

System.out.println( \"After solving (. shows solution, o shows visited)\" );

System.out.println( maze );

}

}

package p2;
	import java.util.Scanner;
	import java.io.File;
	import java.io.FileNotFoundException;
	public class MazeReader {
	private String fileName;
	private Maze maze;
	public MazeReader( String fileName ) {
	this.fileName = fileName;
	this.maze = null;
	}
	public Maze open() throws FileNotFoundException {
	Scanner scanner = new Scanner( new File( this.fileName ));
	int width = scanner.nextInt();
	int height = scanner.nextInt();
	this.maze = new Maze( width, height );
	// Remove new line after int
	scanner.nextLine();
	// ADD STATEMENTS HERE
	// You will need to read in each line using the Scanner, and provide
	// the row number and the line to the addLine method to add it to the Maze
	return this.maze;
	}
	private void addLine( int row, String line ) {
	// ADD STATEMENTS HERE
	}
	public static void main( String[] args ) throws FileNotFoundException {
	MazeReader reader = new MazeReader( \"sampleMaze.txt\" );
	Maze maze = reader.open();
	System.out.println( maze );
	System.out.println( maze.at( new Coordinate( 0, 0 )));
	System.out.println( maze.at( new Coordinate( 0, 1 )));
	}
	}

Solution

import java.io.*;

class Maze

{

   

    class MazeSquare

    {

        public boolean     hasTopWall;

        public boolean     hasRightWall;

        public boolean     hasLeftWall;

        public boolean     hasBottomWall;

        public MazeSquare()

        {

            hasTopWall = hasRightWall = hasLeftWall = hasBottomWall = false;

        }

    }

        class MazeFormatException extends Exception

    {

        public final static int noError = 0;

        public final static int badRowAndColumnCounts = 1;

        public final static int wrongNumberOfEntriesInRow = 2;

        public final static int badEntry = 3;

        public int lineNumber;

        public int problem;

        public MazeFormatException( int line, int prob )

        {

            lineNumber = line;

            problem = prob;

        }

    }

                private int             nRows;

                private int             nColumns;

                MazeSquare[][]          square;

    public static void main( String[] args )

    {

        if( args.length != 1 )

        {

            System.err.println( \"Usage: java Maze mazeFileName\" );

            System.exit( 1 );

        }

        Maze knosos = null;

        try

        {

            knosos = new Maze( args[0] );

        }

        catch( FileNotFoundException e )

        {

            System.err.println( \"Can\'t open \" + args[0] + \". Check your spelling.\" );

            System.exit( 1 );

        }

        catch( IOException e )

        {

            System.err.println( \"Severe input error. I give up.\" );

            System.exit( 1 );

        }

        catch( MazeFormatException e )

        {

            switch( e.problem )

            {

            case MazeFormatException.badRowAndColumnCounts:

                System.err.println( args[0] + \", line \" + e.lineNumber + \": row and column counts expected\" );

                break;

            case MazeFormatException.wrongNumberOfEntriesInRow:

                System.err.println( args[0] + \", line \" + e.lineNumber + \": wrong number of entries\" );

                break;

            case MazeFormatException.badEntry:

                System.err.println( args[0] + \", line \" + e.lineNumber + \": non-hexadecimal digit detected\" );

                break;

            default:

                System.err.println( \"This should never get printed.\" );

                break;

            }

            System.exit( 1 );

        }

        knosos.print( System.out );

    }

    public Maze()

    {

        square = null;

        nRows = nColumns = 0;

    }

    public Maze( String fileName ) throws FileNotFoundException, IOException, MazeFormatException

    {

        BufferedReader in = null;

        in = new BufferedReader( new FileReader( fileName ) );

        load( in );

        in.close();

    }

    public void load( BufferedReader in ) throws MazeFormatException

    {

        String line;

        String[] tokens;

        int lineNumber = 0;

                try

        {

            line = in.readLine();

            lineNumber++;

            tokens = line.split( \"\\\\s+\" );

            nRows = Integer.parseInt( tokens[0] );

            nColumns = Integer.parseInt( tokens[1] );

            if( nRows <= 0 || nColumns <= 0 )

                throw new Exception();

        }

        catch( Exception e )

        {

            throw new MazeFormatException( lineNumber, MazeFormatException.badRowAndColumnCounts );

        }

        // Allocate the 2D array of MazeSquares.

        square = new MazeSquare[nRows][nColumns];

        for( int i=0; i < nRows; i++ )

           for( int j=0; j < nColumns; j++ )

              square[i][j] = new MazeSquare();

        for( int i=0; i < nRows; i++ )

        {

            try

            {

                line = in.readLine();

                lineNumber++;

                tokens = line.split( \"\\\\s+\" );

                if( tokens.length != nColumns )

                    throw new Exception();

            }

            catch( Exception e )

            {

                throw new MazeFormatException( lineNumber, MazeFormatException.wrongNumberOfEntriesInRow );

            }

            for( int j=0; j < nColumns; j++ )

            {

                int            squareValue;

                try

                {

                    squareValue = Integer.parseInt( tokens[j], 16 );

                }

                catch( NumberFormatException e )

                {

                    throw new MazeFormatException( lineNumber, MazeFormatException.badEntry );

                }

                // These are \"bitwise AND\" operations. We\'ll discuss them in class.

                square[i][j].hasTopWall = ((squareValue & 1) != 0);

                square[i][j].hasRightWall = ((squareValue & 2) != 0);

                square[i][j].hasBottomWall = ((squareValue & 4) != 0);

                square[i][j].hasLeftWall = ((squareValue & 8) != 0);

            }

                                }

                }

   

    public void print( PrintStream out )

    {

        int i, j;

        for( i=0; i < nRows; i++ )

        {

            out.print( \'+\' );

            for( j=0; j < nColumns; j++ )

            {

                if( i > 0 && square[i][j].hasTopWall != square[i-1][j].hasBottomWall )

                    out.print( \"xxx+\" );

                else if( square[i][j].hasTopWall )

                    out.print( \"---+\" );

                else

                    out.print( \"   +\" );

            }

            out.println();

            if( nColumns > 0 && square[i][0].hasLeftWall )

                out.print( \'|\' );

            else

              out.print( \' \' );

            for( j=0; j < nColumns; j++ )

            {

                if( j < nColumns - 1 && square[i][j].hasRightWall != square[i][j+1].hasLeftWall )

                    out.print( \"   X\" );

                else if( square[i][j].hasRightWall )

                    out.print( \"   |\" );

                else

                    out.print( \"    \" );

            }

            out.println();

        }

        if( nRows > 0 )

        {

            out.print( \'+\' );

            for( j=0; j < nColumns; j++ )

            {

                if( square[nRows-1][j].hasBottomWall )

                    out.print( \"---+\" );

                else

                    out.print( \"   +\" );

            }

            out.println();

        }

    }

}