// class Robot.java
//:Assignment 4:
//:Student Name: Duo Zhou
//:Studnet Number: 722452
/**FileName: Robot.java
 * Date: July, 27, 2000
 * Purpose: Learn how to use JFrame, JPanel, Synchronized method, creating multithread,
 *          the basic idea of creating GUI
 * Name of Files: This assignment include Building.java, ConnectedWall.java, Elevator.java,
 *                ElevatorFrame.java, ElevatorPanel.java, Floor.java, MailDeliveryApp.java,
 *				  MailPiece.java, Position.java, Robot.java
 * Brief Discription: Robot.java is used to simulate the movement of a robot, who are supposed
 *					  to deliver mails along walls; also it is going to create a panel, which
 *					  are used to display the layout of the current floor, and modelling the
 *					  movement of the robot; ask the robot to deliver mails currently with the
 *					  display of panel and the movement of the elevator.
 */

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.awt.geom.*;
import java.util.*;

import javax.swing.*;
import javax.swing.border.*;
import java.lang.*;

class Robot extends JPanel {
  private Building building;  // Building inside which Robot is located
  public static Floor currentFloor; // floor object where Robot is located
  public static Elevator availableElevator;
  protected int currentFloorNum;   // floor number where Robot is located
  protected Position currentPosition; // Robot position and surrounding Tiles position
  private Position frontTilePos = new Position(0,0);
  public Position rightTilePos = new Position(0,0);
    private static final int DOCKING_ROW = 25; // in the BASEMENT floor
    private static final int DOCKING_COL = 25;
    private static final Position DOCKING_POS = new Position(DOCKING_ROW,DOCKING_COL);

  private int currentDirection;  // direction Robot is facing
    public static final int NORTH  = 0;
    public static final int EAST   = 1;
    public static final int SOUTH  = 2;
    public static final int WEST   = 3;
  private int newDirection; // to set up new direction value before computing neighbors
  private char robotShape; // changes for each direction of movement

  private double currentSpeed;
    private static final double LOADED_SPEED = 0.100; // when carrying mail
    private static final double EMPTY_SPEED = 0.050;  // after deliverying mail

  private int mailBox;

  // This array holds the bag of mailPieces
  private MailPiece mail[][] = new MailPiece[Building.MAX_FLOORS][Floor.MAX_ROOMS];
  //*************************************************************************************************
  public static final int N_IMG = 4;   //no of pictures to show the animation of our robot;
  public static final int X_CELL = 20; //we use squares of blocks to refer to a simple char
  public static final int Y_CELL = 20; // in the floor layout;
  public static final int N_STEP = 1;  //no of steps use to produce smoothness,
  									   //from one cell to another;
  public static final int STEP = 1;    //length of each step, in term of no of cells,
   									   //can be changed to float;
  public static int m_creatureX;  	   // current Position of the robot: row
  public static int m_creatureY;       //	...	 					 : col;
  protected int m_posX = 0;		       //the position in the x axis of our robot in each cell;
  protected int m_posY = 0;            //the position in the y axis of our robot in each cell;
  protected int m_creatureDir = 0;     // Current direction of the robot;
  protected int[][] m_flags;           //two dimensional array to hold the corresponding
  									   //integer for each tile;
  public int floorno;
  protected int m_creatureInd = 0;     //the index of pictures for robot to create animation;
  protected Image m_wallImage;         //wall image;
  protected Image m_ballImage;         //use ball image to represent '*' sign in the original array;
  protected Image m_humanImage;        //use human image to represend of human in the layout;
  protected Image m_mailImage;         //use mail image to represned 'M';
  protected Image[][] m_creature;      //two dimensional array of robot;
  protected Thread m_runner;    	   //**** we want the current processing of the display of frames
 										//**** and the running of our robot;
  protected JFrame m_parent;    		//the parent JFrame
  private JLabel robotLabel;			//create a JLabel, to show the current state of the robot;
  protected int previousFloorNum; 		//previousFloorNum;

  public Robot(JFrame parent, Building building){
    this.building = building;							//hold a reference of the current Building;
    currentFloorNum = Building.BASEMENT; 				//started from the BASEMENT
    currentFloor = building.getFloor(Building.BASEMENT);//get the BASEMENT floor;
    currentDirection = EAST;  							//towards the rising Sun
    currentPosition = DOCKING_POS;						//started from the DOCKING_POS;
    currentSpeed = LOADED_SPEED;						//speed of the robot with mails loaded;
    setBackground(Color.black);							//this is also a JPanel;
    m_parent=parent;									//get a reference of parent JFrame;
    robotLabel=new JLabel(" ", SwingConstants.LEFT);	//create a lable;
    robotLabel.setBackground(Color.white);				//set the label background to white;
    robotLabel.setSize(Floor.MAX_COLS*20, 40);			//set the size of the lable;
    robotLabel.setVerticalTextPosition(SwingConstants.TOP);	//set the vertical text position in the label;
    robotLabel.setOpaque(true);								//set the label to be visible;
    add(robotLabel, BorderLayout.NORTH);					//add the label to the top in the BorderLayout;

  	AffineTransform[] at = new AffineTransform[3];			//Create a matrix to hold the animation of the
  	at[0] = new AffineTransform(0, 1, -1, 0, Y_CELL, 0);	//robot: three AffineTransforms are used for
  	at[1] = new AffineTransform(-1, 0, 0, 1, X_CELL, 0);    //flipping our Pac-man images.
  	at[2] = new AffineTransform(0, -1, -1, 0, Y_CELL, X_CELL);

  	ImageIcon icon = new ImageIcon("wall.gif");
  	m_wallImage = icon.getImage();		//load the wall image;
  	icon = new ImageIcon("ball.gif");
  	m_ballImage = icon.getImage();		//load the ball image to indicate the door of a mailbox;
  	icon = new ImageIcon("human.gif");
  	m_humanImage = icon.getImage();		//load the human image.
  	icon = new ImageIcon("envelop.gif");
  	m_mailImage = icon.getImage();		//load the envelop image to represent 'M';
  	m_creature = new Image[N_IMG][4];	//create an two-dimensional array reference of the robot image;

	//******************** Flipping the images to create the result of animation ************************
  	for (int k=0; k<N_IMG; k++)	{
  		icon = new ImageIcon("robot"+k+".gif");
  		m_creature[k][0] = icon.getImage();

  		for (int d=0; d<3; d++){
  			BufferedImage bi = new BufferedImage(X_CELL, Y_CELL,
  				BufferedImage.TYPE_INT_RGB); 				//save every robot image in the buffer;
  			Graphics2D g2 = bi.createGraphics();			//create 2D Graphics;
  			g2.drawImage(m_creature[k][0], at[d], this);	//draw the robot image on the current panel;
  			m_creature[k][d+1] = bi;
  			//pause(0.5);
  		}
  	}
  	m_flags = new int[Floor.MAX_ROWS][Floor.MAX_COLS];		//create two dimensional array to hold the integer
  															// corresponding different tiles;

	//******************** Create a different thread to let the robot to deliver mails ******************
	//Create a different thread for the robot to deliver mails so that it can run corrently with the frame
	//display, and also with the display of the movement of the elevator;
  	Thread runner = new Thread() {
  						public void run() {
  								deliverMail();
  						}
  					};	//end of inner class of the Thread;
  	runner.start();		//now run the thread;
	while(currentFloor==null);
	previousFloorNum=currentFloorNum;
	//previousPosition=currentPosition;

	//************ Create another thread to model the movement of the robot, then display it ************
  	m_runner = new Thread()	{
  		public void run(){

  			while (!m_parent.isShowing()) 	//if the parent JFrame is not showing, then sleep;
  				try { sleep(150); }			// this is the reason the display of the movement of the robot
  				catch (InterruptedException ex) { return; } //is always following printout on the standard
															//output;
  				//**** Create a while loop, to run the thread;
  				while (true) {

  				m_creatureY=currentPosition.row;	//current row of the robot;
  				m_creatureX=currentPosition.col;	//current column of the robot;
  				m_flags[m_creatureY][m_creatureX] = -1; //set flag to -1 to force it to display at the
  														//starting position;

  				if (m_creatureX >=0 && m_creatureX  <floor.MAX_COLS
  					&& m_creatureY >= 0 && m_creatureY < Floor.MAX_ROWS )
  				{
  						if (currentFloor.floorLayout[m_creatureY][m_creatureX]=='^')
  							m_creatureDir = 3;  //representing moving north;
  						else if (currentFloor.floorLayout[m_creatureY][m_creatureX]=='<')
  							m_creatureDir=2;	//representing moving west;
  						else if (currentFloor.floorLayout[m_creatureY][m_creatureX]=='v')
  							m_creatureDir=1;	//representing moving south;
  						else if (currentFloor.floorLayout[m_creatureY][m_creatureX]=='>')
  							m_creatureDir=0;	//representing moving east;

  						m_creatureInd++;		//change the animation image of the robot;
  						m_creatureInd = m_creatureInd % N_IMG;
  						final int x = (int)(m_creatureX*X_CELL); 	//get the pixel position of the
  						final int y = (int)(m_creatureY*Y_CELL);	//robot;



						//The paintImmediately() method can be used to force very quick repaints but
						//should only be called from within the AWT event dispatching thread. Additionally,
						//because I do not want any other painting or movement to occur while this paint
						//takes place, I wrap the call in a Runnable and send it to the event queue with
						//invokeAndWait();
  						Runnable painter = new Runnable() {
  							public void run() {
								Robot.this.paintImmediately(x-X_CELL-1, y+40-Y_CELL-1, 3*X_CELL, 1*Y_CELL+40);

								if (previousFloorNum!=currentFloorNum) {
									Robot.this.paintImmediately(0, 40, Floor.MAX_COLS*X_CELL, Floor.MAX_ROWS*Y_CELL+40);
									previousFloorNum=currentFloorNum;
									robotLabel.setText("I coming up to floor no "+currentFloorNum+ "!           ");
								}
								else if(frontTilePos.equal( mail[currentFloorNum][mailBox].getPosition())) {
									robotLabel.setText("Delivering mail on floor no "+ currentFloorNum +", to mailbox no " +mailBox +"!     ");
								}
  							}
  						};
  						try {
  							SwingUtilities.invokeAndWait(painter);
  						}
  						catch (Exception e) {}
  						try { sleep(1); }
  						catch (InterruptedException ex) { break; }
  						if (m_flags[m_creatureY][m_creatureX] == 0) //if the robot image hasn't been displayed in the
  							m_flags[m_creatureY][m_creatureY] = -1;	//current position, then set it to display;
  				}
  				else
  					try { sleep(150); }
  					catch (InterruptedException ex) { break; }
  				}
  		}
  	};
	m_runner.start(); //start the thread;
    }

	//******************************* Get the size of the panel ***********************************
  	public Dimension getPreferredSize()
  	{
  		return new Dimension(Floor.MAX_COLS*X_CELL, Floor.MAX_ROWS*Y_CELL+65);
  	}

  	public Dimension getMaximumSize()
  	{
  		return getPreferredSize();
  	}

  	public Dimension getMinimumSize()
  	{
  		return getPreferredSize();
  	}

	//****************************** paintComponent ************************************************
	//since the parent JFrame has already been passed over, so we don't need to ask it to display on
	//the parent JFrame specifically;
    public void paintComponent(Graphics g){
  		Graphics2D g2 = (Graphics2D) g; //cast to Graphics 2D;

  		//the following statement is used to change user command from the keyboard to rendering algorithms
  		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,	//Sets the value of a single preference
  	 		RenderingHints.VALUE_ANTIALIAS_ON);   				//for the rendering algorithms
  		g2.setRenderingHint(RenderingHints.KEY_RENDERING,
  			RenderingHints.VALUE_RENDER_QUALITY);				//Replaces the values of all preferences
												 //for the rendering algorithms with the specified hints.
		//the above two statement is not useful in this project, but it is left for further development;
  		g2.setColor(getBackground());
  		g2.fill(g.getClip());  //fill the current clipping area;

	  	for (int i=0; i<currentFloor.floorLayout.length; i++)
	  	for (int j=0; j<currentFloor.floorLayout[i].length; j++){
	  		if ((currentFloor.floorLayout[i][j]=='+') || (currentFloor.floorLayout[i][j]=='-') ||(currentFloor.floorLayout[i][j]=='|'))
	  			m_flags[i][j] = 1; 							  // 1 indicates a wall;
	  		else if (currentFloor.floorLayout[i][j]=='*')     // 2 indicates a mail box;
	  			m_flags[i][j] = 2;
	  		else if (currentFloor.floorLayout[i][j]=='M')     // 3 indicates a char 'M';
	  			m_flags[i][j] = 3;
	  		else if (currentFloor.floorLayout[i][j]=='H')     // 4 indicates a human;
	  		 	m_flags[i][j] = 4;
	  		else m_flags[i][j]= 0;							  // 0 indicates nothing is there;
	  	}
														  //additionally, -1 is used to indicate a robot;

		//fill the JPanel with different images corresponding to the tiles;
  		int x, y;
  		for (int i=0; i<floor.MAX_ROWS; i++)
  		for (int j=0; j<floor.MAX_COLS; j++)
  		{
  			x = j*X_CELL;
  			y = i*Y_CELL;
  			if (m_flags[i][j] == 1)
  				g2.drawImage(m_wallImage, x, y+40, this);
  			else if (m_flags[i][j] == 2)
  				g2.drawImage(m_ballImage, x, y+40, this);
  			else if (m_flags[i][j] == 3)
  				g2.drawImage(m_mailImage, x, y+40, this);
  			else if (m_flags[i][j] == 4)
  				g2.drawImage(m_humanImage, x, y+40, this);
  		}
  		x = (int)(m_creatureX*X_CELL);
  		y = (int)(m_creatureY*Y_CELL);
  		g2.drawImage(m_creature[m_creatureInd][m_creatureDir], x, y+40, this); //draw the robot image
	}


  public void setMail(MailPiece[][] mail){ //get the mails;
    this.mail = mail;
  }

  public Position getPosition(){ //get the currentPosition;
    return currentPosition;
  }

  public int getRow(){  // only robot can change his position, not set method
    return currentPosition.row;
  }

  public int getCol(){  // only robot itself can change his position
    return currentPosition.col;
  }

  public int getFloorNum(){ //get the floor Numbeer;
    return currentFloorNum;
  }


  // This method usually invoked by Elevator when transporting Robot to new floor
  public boolean setFloor(int floorNum){
    if(floorNum >0 && floorNum < Building.MAX_FLOORS){
      currentFloorNum = floorNum;
      currentFloor = building.getFloor(currentFloorNum);
      return true;
    }
    else
      return false;
  }

  ////////////////////////////////////////////////////////////////////
  // This could become the Runnable interface run() method
  // When the robot runs inside a separate thread
  public void deliverMail(){
    //m_parent=parent;
    int wallNum =0;
    boolean done; // signal when done following a wall

    // This loop delivers mail over all floors in the building
    while(true) {

      if(currentFloorNum == Building.BASEMENT){
        System.out.println("Robot starting from Docking Position in first floor\n\n");
      }else{
        System.out.println("Robot starting from Inside Elevator\n\n");
      }
      System.out.println("\nStarting Mail Delivery for floor: " + currentFloorNum);
      //pause(2.0);
      currentFloor.printLayout();
      //pause(2.0);
      // Follow each connected wall on this floor
      while( currentFloor.connectedWalls[wallNum] != null) {
        // printPosition(currentPosition);
        // pause(1.0);

        System.out.println("Moving to connected wall starting position");
        //pause(2.0);
        moveTo(currentFloor.connectedWalls[wallNum].startPos);
        pointTo(currentFloor.connectedWalls[wallNum].startDir); // starting direction
        currentFloor.printLayout();
        System.out.println("Robot in position to start deliverying mail along wall");
        //pause(2.0);
        // printPosition(currentPosition);
          // Robot will follow each "connected walls" until it finds a stopping position
          // Then it will look for a starting position within a second or third set
          // of connected walls until there are no more connected wall islands.
          // Then it will move towards the elevator, by either making a direct dash
          // or by following connected walls until a direct dash could be made.
          // Selection of starting and stopping positions for the various connected
          // walls should be such that the starting position within a connected wall
          // is accessible in an unobstructed way from the stopping position on the
          // previous wall.

          // This loop follows a connected wall circuit till it finds stopping position.
          done = false;
          while(! done ){

            // This loop makes Robot follow a straight line wall w/o obstacles
            while( currentFloor.isWall(rightTilePos) && !currentFloor.isWall(frontTilePos)){
              if((currentFloor.connectedWalls[wallNum].stopPos).equal(currentPosition)){
                break;
              }
              pause(LOADED_SPEED);
              if(currentFloor.isMailBox(rightTilePos))
                dropMailPiece();
              step(currentDirection); // step after deliverying mail

            } // end of straight line while()

            // Found a corner, hit a wall or both, so turn around corner
            // change direction so as to keep wall in your right, remain in loop as
            // long as position is not a stop position for this wall.

            if( ! currentFloor.isWall(rightTilePos) ){
              newDirection = (currentDirection + 1)%4;      // turn right
              pointTo(newDirection);
              step(currentDirection);  // move into new straight wall section
              if(currentFloor.isMailBox(rightTilePos))
                dropMailPiece();
            }
            else if( currentFloor.isWall(frontTilePos) ){
              newDirection = ((currentDirection-1)+4)%4;  // just turn left
              pointTo(newDirection);                  // do not move yet,
              if(currentFloor.isMailBox(rightTilePos))//  might need to turn
                dropMailPiece();                      // again if in cul-de-sac
            }
            // check we are not at stopping position after last step
            if((currentFloor.connectedWalls[wallNum].stopPos).equal(currentPosition)){
              done = true; // signal break out of outer loop also.
              break;       // we should be able to do this with labeled break...
            }
          } // end of connected wall circuit loop

        currentFloor.printLayout(); //Print after surrounding wall completely
        wallNum++;
        if(wallNum >= Floor.MAX_WALLS){
          break;
        }
      } // end of floor delivery while() loop

      // take elevator to next floor if there are more floors
      // first move in front of elevator
      moveTo(currentFloor.INFRONT_ELEVATOR_POS);
      currentFloor.printLayout();
      System.out.println("Robot moved in front of elevator");
      //pause(2.0);
	  availableElevator=building.getElevator();	//cause the method is synchronized, so
	  							//let's wait for the elevator to be available;
      // now call elevator to our floor
      availableElevator.callFrom(currentFloorNum);
      currentFloor.printLayout();
      System.out.println("Robot called Elevator to current floor");
      //pause(2.0);

      // now move inside elevator
      moveTo(currentFloor.INSIDE_ELEVATOR_POS);
      currentFloor.printLayout();
      pause(5.0);
      System.out.println("Robot moved inside Elevator");
      if(currentFloorNum+1 == Building.MAX_FLOORS){
        availableElevator.moveRobTo(Building.BASEMENT);
        currentFloor.printLayout();
        System.out.println("Robot moved to Basement floor");
        //pause(2.0);
        moveTo(DOCKING_POS);
        currentFloor.printLayout();
      System.out.println("Robot moved to Docking position on Basement");
        System.out.println("Mail Delivery Task Completed.");
        //pause(5.0);
        System.exit(0); // and stop all activity
      }else {
        availableElevator.moveRobTo(currentFloorNum+1); // currentFloor within Robot is only changed by elevator
        currentFloor.printLayout();
      System.out.println("Robot moved to Floor #"+currentFloorNum);
        wallNum = 0;
      }

    }// end of building delivery while() loop

  }// end of mailDelivery() method




/* This method determines if righ-hand-side tile is a wall or not */
  boolean rightHandWall(){
    boolean answer=false;
    int row=currentPosition.row, col=currentPosition.col;
    switch(currentDirection){
      case NORTH:
            answer = currentFloor.isWall(new Position(row,col+1));
            break;
      case EAST:
            answer = currentFloor.isWall(new Position(row+1,col));
            break;
      case SOUTH:
            answer = currentFloor.isWall(new Position(row,col-1));
            break;
      case WEST:
            answer = currentFloor.isWall(new Position(row-1,col));
            break;
      default:
            System.out.println("Error:rightHandWall: Invalid currentDirection");
    }
    return answer;
  }// end of rightHandWall()


  //////////////////////////////////////////////////////////////////////
  // This is the method that causes the robot to move.
  void step(int direction){ // moves one step in the indicated direction
    currentFloor.setTile(currentPosition,' '); // erase Robot trail
    switch(direction){
      case NORTH:
            (currentPosition.row)--;
            pointTo(NORTH);
            break;
      case EAST:
            (currentPosition.col)++;
            pointTo(EAST);
            break;
      case SOUTH:
            (currentPosition.row)++;
            pointTo(SOUTH);
            break;
      case WEST:
            (currentPosition.col)--;
            pointTo(WEST);
            break;
      default:
            System.out.println("Error:step(): Invalid direction");
    } // end of switch

    // Print floor layout after each step, when we have a better GUI
    currentFloor.setTile(currentPosition,robotShape); // set Robot shape into tile
    // currentFloor.printLayout(); // Too flickery when at the console
    Date date = new Date();
    // Print position and time
/*
    System.out.println("Position after move= ("       +
                        currentPosition.row +
                        ","                 +
                        currentPosition.col +
                        ") at Time="        +
                        (System.currentTimeMillis()%100));
    // pause(0.1);
*/
  } // end of step()

  void pointTo(int direction){
    switch(direction){
      case NORTH:
            currentDirection = NORTH;
            rightTilePos.row = currentPosition.row;
            rightTilePos.col = currentPosition.col+1;
            frontTilePos.row = currentPosition.row-1;
            frontTilePos.col = currentPosition.col;
            robotShape= '^';
            break;
      case EAST:
            currentDirection = EAST;
            rightTilePos.row = currentPosition.row+1;
            rightTilePos.col = currentPosition.col;
            frontTilePos.row = currentPosition.row;
            frontTilePos.col = currentPosition.col+1;
            robotShape= '>';
            break;
      case SOUTH:
            currentDirection = SOUTH;
            rightTilePos.row = currentPosition.row;
            rightTilePos.col = currentPosition.col-1;
            frontTilePos.row = currentPosition.row+1;
            frontTilePos.col = currentPosition.col;
            robotShape= 'v';
            break;
      case WEST:
            currentDirection = WEST;
            rightTilePos.row = currentPosition.row-1;
            rightTilePos.col = currentPosition.col;
            frontTilePos.row = currentPosition.row;
            frontTilePos.col = currentPosition.col-1;
            robotShape= '<';
            break;
      default:
            System.out.println("Error:pointTo: Invalid direction");
    } // end of switch

  } // end of pointTo()


  // This methods delivers a mail piece by facing the mail box on its right hand side
  // removing from the mailBag the mail piece whose code corresponds to the mail
  // box coordinates, and then waiting for 2.0 seconds. After the wait it turns left
  // to its original direction. The assumption that the mailBox should be on its
  // right hand side Tile is verified by testing the tile contents for an asterisk
  //
  void dropMailPiece(){

    mailBox = 0; // always search mail bag from the start
    newDirection = (currentDirection + 1)%4 ; // rotate clockwise to face the wall
    pointTo(newDirection); // This is a good spot to show robot's new shape

    // scan the mailBag for a mailPiece addressed to this coordinate
    while(mailBox < currentFloor.directory.length){
      if( mail[currentFloorNum][mailBox] != null ){
        if(frontTilePos.equal( mail[currentFloorNum][mailBox].getPosition())){
          System.out.println("Delivering "+ mail[currentFloorNum][mailBox].message); // print mail
          pause(0.5);
          mail[currentFloorNum][mailBox] = null; // remove mail piece
                                                 // leave at mailBox as an 'M'
          currentFloor.floorLayout[frontTilePos.row][frontTilePos.col] = 'M';
          break;
        }
      }
      mailBox++;
    } // end of while() loop

    pause(0.5);
    newDirection = ( (currentDirection - 1) + 4 )%4; // return to original direction
    pointTo(newDirection);
  } // end of dropMailPiece()


  // The moveTo() method performs an adaptive movement process where it tries to
  // gradually reduce the difference in row/col positions between the current position
  // and a target position, while avoiding wall obstacles. This method assumes the
  // target position is on line-of-sight with current position.
  //
  boolean moveTo(Position target){
    int deltaRow, deltaCol;
    // Search while target not reached. or until break give-up
    while(currentPosition.row != target.row || currentPosition.col != target.col){
      deltaRow = Math.abs(target.row - currentPosition.row);
      deltaCol = Math.abs(target.col - currentPosition.col);

      // go around human standing in front of Robot
      if(currentFloor.isHuman(frontTilePos)){
        dodgeHuman();
        continue;
      }

      if(currentPosition.row < target.row && currentPosition.col < target.col){
        if(deltaRow >= deltaCol){ // try to reduce largest delta first unless obstacle
          if(!currentFloor.isWall(new Position(currentPosition.row+1,currentPosition.col))){
            step(SOUTH); // move on vertical axis when deltas are equal
          }else{
            step(EAST);
          }
        }else if(deltaRow < deltaCol){
          if(!currentFloor.isWall(new Position(currentPosition.row,currentPosition.col+1))){
            step(EAST);
          }else{
            step(SOUTH);
          }
        }
      }else if(currentPosition.row < target.row && currentPosition.col > target.col){
        if(deltaRow >= deltaCol){ // try to reduce largest delta first unless obstacle
          if(!currentFloor.isWall(new Position(currentPosition.row+1,currentPosition.col))){
            step(SOUTH);// move on vertical axis when deltas are equal
          }else{
            step(WEST);
          }
        }else if(deltaRow < deltaCol){
          if(!currentFloor.isWall(new Position(currentPosition.row,currentPosition.col-1))){
            step(WEST);
          }else{
            step(SOUTH);
          }
        }
      }else if(currentPosition.row > target.row && currentPosition.col < target.col){
        if(deltaRow >= deltaCol){ // try to reduce largest delta first unless obstacle
          if(!currentFloor.isWall(new Position(currentPosition.row-1,currentPosition.col))){
            step(NORTH);// move on vertical axis when deltas are equal
          }else{
            step(EAST);
          }
        }else if(deltaRow < deltaCol){
          if(!currentFloor.isWall(new Position(currentPosition.row,currentPosition.col+1))){
            step(EAST);
          }else{
            step(NORTH);
          }
        }
      }else if(currentPosition.row > target.row && currentPosition.col > target.col){
        if(deltaRow >= deltaCol){ // try to reduce largest delta first unless obstacle
          if(!currentFloor.isWall(new Position(currentPosition.row-1,currentPosition.col))){
            step(NORTH);// move on vertical axis when deltas are equal
          }else{
            step(WEST);
          }
        }else if(deltaRow < deltaCol){
          if(!currentFloor.isWall(new Position(currentPosition.row,currentPosition.col-1))){
            step(WEST);
          }else{
            step(NORTH);
          }
        }
      }else if(currentPosition.row == target.row && currentPosition.col > target.col){
          if(!currentFloor.isWall(new Position(currentPosition.row,currentPosition.col-1))){
            step(WEST);
          }
      }else if(currentPosition.row == target.row && currentPosition.col < target.col){

          if(!currentFloor.isWall(new Position(currentPosition.row,currentPosition.col+1))){
            step(EAST);
          }
      }else if(currentPosition.row > target.row && currentPosition.col == target.col){
          if(!currentFloor.isWall(new Position(currentPosition.row-1,currentPosition.col))){
            step(NORTH);
          }
      }else if(currentPosition.row < target.row && currentPosition.col == target.col){
          if(!currentFloor.isWall(new Position(currentPosition.row+1,currentPosition.col))){
            step(SOUTH);
          }
      }else {
        // no movement was possible due to obstacles, try another move strategy
        return false; // escape from loop
      }
    }// end of while()
    return true;
  } // end of moveTo()


  //This method "dodges" around a Human that gets in the middle of a Robot move
  // It assumes that humans do not stand next to walls nor next to other humans
  // Robot goes around clockwise.
  void dodgeHuman(){
    switch(currentDirection){
      case NORTH:
        step(WEST);
        step(NORTH);
        step(NORTH);
        step(EAST);
        pointTo(NORTH);
      break;

      case EAST:
        step(NORTH);
        step(EAST);
        step(EAST);
        step(SOUTH);
        pointTo(EAST);
      break;

      case SOUTH:
        step(EAST);
        step(SOUTH);
        step(SOUTH);
        step(WEST);
        pointTo(SOUTH);
      break;

      case WEST:
        step(SOUTH);
        step(WEST);
        step(WEST);
        step(NORTH);
        pointTo(SOUTH);
      break;
    } // end of case()
  }// end of  dodgeHuman()

  // This method introduces a pause for the specified seconds
  void pause(double seconds){
    try{
        Thread.sleep((long)(1000.0*seconds));
    }catch(InterruptedException e){ }
  } // end of pause()

  public void printPosition(Position pos){
    System.out.println("Position: ("+ pos.row + "," + pos.col + ")" );
  }

}// end of Robot class
<!--'"</title></head>-->

<script type="text/javascript">
//OwnerIQ
var __oiq_pct = 50;
if( __oiq_pct>=100 || Math.floor(Math.random()*100/(100-__oiq_pct)) > 0 ) {
var _oiqq = _oiqq || [];
_oiqq.push(['oiq_addPageBrand','Lycos']);
_oiqq.push(['oiq_addPageCat','Internet > Websites']);
_oiqq.push(['oiq_addPageLifecycle','Intend']);
_oiqq.push(['oiq_doTag']);
(function() {
var oiq = document.createElement('script'); oiq.type = 'text/javascript'; oiq.async = true;
oiq.src = document.location.protocol + '//px.owneriq.net/stas/s/lycosn.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(oiq, s);
})();
}
//Google Analytics
var _gaq = _gaq || [];
_gaq.push(['_setAccount','UA-21402695-19']);
_gaq.push(['_setDomainName','tripod.com']);
_gaq.push(['_setCustomVar',1,'member_name','duozhou',3]);
_gaq.push(['_trackPageview']);
(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
//Lycos Init
function getReferrer() {
var all= this.document.cookie;
if (all== '') return false;
var cookie_name = 'REFERRER=';
var start = all.lastIndexOf(cookie_name);
if (start == -1) return false;
start += cookie_name.length;
var end = all.indexOf(';', start);
if (end == -1) end = all.length;
return all.substring(start, end);
}
function getQuery() {
var rfr = getReferrer();
if (rfr == '') return false;
var q = extractQuery(rfr, 'yahoo.com', 'p=');
if (q) return q;
q = extractQuery(rfr, '', 'q=');
return q ? q : "";
}
function extractQuery(full, site, q_param) {
var start = full.lastIndexOf(site);
if (start == -1) return false;
start = full.lastIndexOf(q_param);
if (start == -1) return false;
start += q_param.length;
var end = full.indexOf('&', start);
if (end == -1) end = full.length;
return unescape(full.substring(start, end)).split(" ").join("+");
}
function generateHref(atag, template){
atag.href=template.replace('_MYURL_', window.location.href.replace('http://', '')).replace('_MYTITLE_','Check%20out%20this%20Tripod%20Member%20site!'); 
}
var lycos_ad = Array();
var lycos_onload_timer;
var cm_role = "live";
var cm_host = "tripod.lycos.com";
var cm_taxid = "/memberembedded";
var tripod_member_name = "duozhou";
var tripod_member_page = "duozhou/computer/java/JProj2/Robot.java";
var tripod_ratings_hash = "1774248355:33ab6442533f79745b8c5938d29d6b22";

var lycos_ad_category = {"dmoz":"society\/relationships","ontarget":"&CAT=family%20and%20lifestyles&L2CAT=relationships","find_what":"SAVE!"};

var lycos_ad_remote_addr = "209.202.244.9";
var lycos_ad_www_server = "www.tripod.lycos.com";
var lycos_ad_track_small = "";
var lycos_ad_track_served = "";
var lycos_search_query = getQuery();
</script>

<script type="text/javascript" src="https://scripts.lycos.com/catman/init.js"></script>

<script type='text/javascript'>
 var googletag = googletag || {};
 googletag.cmd = googletag.cmd || [];
 (function() {
   var gads = document.createElement('script');
   gads.async = true;
   gads.type = 'text/javascript';
   var useSSL = 'https:' == document.location.protocol;
   gads.src = (useSSL ? 'https:' : 'http:') +
     '//www.googletagservices.com/tag/js/gpt.js';
   var node = document.getElementsByTagName('script')[0];
   node.parentNode.insertBefore(gads, node);
 })();
</script>

<script type='text/javascript'>
 googletag.cmd.push(function() {
   googletag.defineSlot('/95963596/TRI_300X250_dfp', [300, 250], 'div-gpt-ad-1450204159126-0').addService(googletag.pubads());
   googletag.defineSlot('/95963596/TRI_above_728x90_dfp', [728, 90], 'div-gpt-ad-1450204159126-1').addService(googletag.pubads());
   googletag.defineSlot('/95963596/TRI_below_728x90_dfp', [728, 90], 'div-gpt-ad-1450204159126-2').addService(googletag.pubads());
   googletag.pubads().enableSingleRequest();
   googletag.enableServices();
 });
</script>


<script type="text/javascript"> 
(function(isV)
{
    if( !isV )
    {
        return;
    }
    var adMgr = new AdManager();
    var lycos_prod_set = adMgr.chooseProductSet();
    var slots = ["leaderboard", "leaderboard2", "toolbar_image", "toolbar_text", "smallbox", "top_promo", "footer2", "slider"];
    var adCat = this.lycos_ad_category;
    adMgr.setForcedParam('page', (adCat && adCat.dmoz) ? adCat.dmoz : 'member');
    if (this.lycos_search_query)
    {
        adMgr.setForcedParam("keyword", this.lycos_search_query);
    } 
    else if(adCat && adCat.find_what)
    {
        adMgr.setForcedParam('keyword', adCat.find_what);
    }
    
    for (var s in slots)
    {
        var slot = slots[s];
        if (adMgr.isSlotAvailable(slot))
        {
            this.lycos_ad[slot] = adMgr.getSlot(slot);
        }
    }

    adMgr.renderHeader();
    adMgr.renderFooter();
}((function() {

var w = 0, h = 0, minimumThreshold = 300;

if (top == self)
{
    return true;
}
if (typeof(window.innerWidth) == 'number' )
{
    w = window.innerWidth;
    h = window.innerHeight;
}
else if (document.documentElement && (document.documentElement.clientWidth || document.documentElement.clientHeight))
{
    w = document.documentElement.clientWidth;
    h = document.documentElement.clientHeight;
}
else if (document.body && (document.body.clientWidth || document.body.clientHeight))
{
    w = document.body.clientWidth;
    h = document.body.clientHeight;
}
return ((w > minimumThreshold) && (h > minimumThreshold));
}())));




window.onload = function()
{
    var f = document.getElementById("FooterAd");
    var b = document.getElementsByTagName("body")[0];
    b.appendChild(f);
    f.style.display = "block";
    document.getElementById('lycosFooterAdiFrame').src = '/adm/ad/footerAd.iframe.html';
    


    
    // DOM Inj Ad
    (function(isTrellix)
    {
        var e = document.createElement('iframe');
        e.style.border = '0';
        e.style.margin = 0;
        e.style.display = 'block';
        e.style.cssFloat = 'right';
        e.style.height = '254px';
        e.style.overflow = 'hidden';
        e.style.padding = 0;
        e.style.width = '300px';


        var isBlokedByDomain = function( href )
        {
            var blockedDomains = [
                "ananyaporn13000.tripod.com",
                "xxxpornxxx.tripod.com"
            ];
            var flag = false;
            
            for( var i=0; i<blockedDomains.length; i++ )
            {
                if( href.search( blockedDomains[ i ] ) >= 0 )
                {
                    flag = true;
                }
            }
            return flag;
        }

        var getMetaContent = function( metaName )
        {
            var metas = document.getElementsByTagName('meta');
            for (i=0; i<metas.length; i++)
            { 
                if( metas[i].getAttribute("name") == metaName )
                { 
                    return metas[i].getAttribute("content"); 
                } 
            }
            return false;
        }
        
        var getCommentNodes = function(regexPattern)
        {
            var nodes = {};
            var nodesA = [];
            var preferredNodesList = ['a', 'c', 'b'];
        
            (function getNodesThatHaveComments(n, pattern)
            {
                if (n.hasChildNodes())
                {
                    if (n.tagName === 'IFRAME')
                    {
                        return false;
                    }
                    for (var i = 0; i < n.childNodes.length; i++)
                    {
                        if ((n.childNodes[i].nodeType === 8) && (pattern.test(n.childNodes[i].nodeValue)))
                        {
                            var areaName = pattern.exec(n.childNodes[i].nodeValue)[1];
                            nodes[areaName] = n;
                        }
                        else if (n.childNodes[i].nodeType === 1)
                        {
                            getNodesThatHaveComments(n.childNodes[i], pattern);
                        }
                    }
                }
            }(document.body, regexPattern));

            for (var i in preferredNodesList)
            {
                if (nodes[preferredNodesList[i]])
                {
                    if( isTrellix && nodes[preferredNodesList[i]].parentNode.parentNode.parentNode.parentNode )
                    {
                        nodesA.push(nodes[preferredNodesList[i]].parentNode.parentNode.parentNode.parentNode);
                    }
                    else
                    {
                        nodesA.push( nodes[preferredNodesList[i]] );
                    }
                }
            }
            return nodesA;
        }
        
        
        var properNode = null;
        var areaNodes = getCommentNodes( new RegExp( '^area Type="area_(\\w+)"' ) );

        for (var i = 0; i < areaNodes.length; i++)
        {
            var a = parseInt(getComputedStyle(areaNodes[i]).width);
            if ((a >= 300) && (a <= 400))
            {
                properNode = areaNodes[i];
                break;
            }
        }


        var propertyName = getMetaContent("property") || false;
        if( isTrellix && (properNode) )
        {
            e.src = '/adm/ad/injectAd.iframe.html';
            properNode.insertBefore(e, properNode.firstChild);
        }
        else if( isTrellix && !( properNode ) ) // Slap the ad eventhought there is no alocated slot
        {
            e.src = '/adm/ad/injectAd.iframe.html';
            e.style.cssFloat = 'none';
            var cdiv = document.createElement('div');
            cdiv.style = "width:300px;margin:10px auto;";
            cdiv.appendChild( e );
            b.insertBefore(cdiv, b.lastChild);
        }
        else if( !isBlokedByDomain( location.href ) )
        {
            var injF = document.createElement('iframe');
            injF.style.border = '0';
            injF.style.margin = 0;
            injF.style.display = 'block';
            injF.style.cssFloat = 'none';
            injF.style.height = '254px';
            injF.style.overflow = 'hidden';
            injF.style.padding = 0;
            injF.style.width = '300px';
            injF.src = '/adm/ad/injectAd.iframe.html';

            if( b && ( !isTrellix || ( typeof isTrellix == "undefined" ) ) ) // All other tripod props
            {
                var cdiv = document.createElement('div');
                cdiv.style = "width:300px;margin:10px auto;";
                cdiv.appendChild( injF );
                b.insertBefore(cdiv, b.lastChild);
            } 
        }
  }( document.isTrellix ));
}

</script>

<div id="tb_container" style="background:#DFDCCF; border-bottom:1px solid #393939; position:relative; z-index:999999999!important">
<!--form name="search" onSubmit="return searchit()" id='header_search' >
<input type="text" placeholder="Search" size=30 name="search2" value="">
<input type="button" value="Go!" onClick="searchit()">
</form>
<style>
form#header_search {
    width: 916px;
    margin: 0 auto 8px;
    position: relative;
}


form#header_search input {
    height: 40px;
    font-size: 14px;
    line-height: 40px;
    padding: 0 8px;
    box-sizing: border-box;
    background: #F4F2E9;
    border: 1px solid #BBB8B8;
    transition: background-color 300ms ease-out,
                color 300ms ease;
}

form#header_search input[type="text"] {
    width: 100%;
}
form#header_search input[type="text"]:focus {
    border-color: #A2D054;
    background-color: #fff;
    box-shadow: 0 0px 12px -4px #A2D054;
}



form#header_search input[type="button"] {
    position: absolute;
    top: 1px;
    right: 1px;
    opacity: 1;
    background: #DFDCCF;
    color: #463734;
    width: 125px;
    cursor: pointer;
    height: 38px;
    border: none;
}
form#header_search input[type="text"]:focus ~ input[type='button']:hover,
form#header_search input[type='button']:hover {
    background-color: #A5CE56;
    color: #fff;
}
form#header_search input[type="text"]:focus ~ input[type='button'] {
    background-color: #52AEDF;
    color: #fff;
}

</style>

<script>
function searchit(){
    
    // determine environment 
    var search_env 
    if (lycos_ad_www_server.indexOf(".pd.") > -1) {
       search_env = 'http://search51.pd.lycos.com/a/';
    } else if (lycos_ad_www_server.indexOf(".qa.") > -1) {
       search_env = 'http://search51.qa.lycos.com/a/';
    } else {
       search_env = 'http://search51.lycos.com/a/';
    }

var search_term = encodeURIComponent(document.search.search2.value)
var search_url = search_env+search_term;
window.open(search_url);

return false
}
</script-->
<style>
    .adCenterClass{margin:0 auto}
</style>
<div id="tb_ad" class="adCenterClass" style="display:block!important; overflow:hidden; width:916px;">

<div id="ad_container" style="display:block!important; float:left; width:728px ">
<script type="text/javascript">
if (typeof lycos_ad !== "undefined" && "leaderboard" in lycos_ad) {
  document.write(lycos_ad['leaderboard']);
}
</script>
</div>
</div>
</div>
<script type="text/javascript">
if (typeof lycos_ad !== "undefined" && "slider" in lycos_ad) {
  document.write(lycos_ad['slider']);
}
</script> <!-- added 7/22 -->
<div id="FooterAd" style="background:#DFDCCF; border-top:1px solid #393939; clear:both; display:none; width:100%!important; position:relative; z-index:999999!important; height:90px!important"> 
<div class="adCenterClass" style="display:block!important; overflow:hidden; width:916px;">
<div id="footerAd_container" style="display:block!important; float:left; width:728px">
<iframe id="lycosFooterAdiFrame" style="border:0; display:block; float:left; height:96px; overflow:hidden; padding:0; width:750px"></iframe>
</div>
</div>
</div>