how to make this java code Random using OO?

[Andres John]

the prof is asking me to do this
Create an alternate KtR that solves knight's tour problem for an 8 by 8 board by randomly picking a move from 0 to 7 and if legal make the move. If not legal, try doing this 100 times and if no legal moves after 100 tries abort the game as a failure.
If you make 64 moves print the board.

package arr;

import javax.swing.JOptionPane;

public class KtH {
private Board b;
private int ctr=0; // this counts the moves the knight makes
private int [] lastMove=new int[2]; // we need a 1 x 2 array to store (x,y) the pos. of last move
private int h[]={-2,-2,-1,-1,1,1,2,2}; // this is the change in column
private int v[]={-1,1,2,-2,2,-2,1,-1}; // this is change in row
private int adj[][]; // adjacency matrix keeping track of # of moves left from every square on board b
private int r,c,dim;
orivate int randomN;

public KtH(int dim, int r, int c){
    adj=new int [dim][dim];
    b=new Board(dim); // instantiate a Board object b to dimension dim x dim
    b.setElement(r, c, ++ctr); // set the board at position (r,c) to 1
    lastMove[0]=r;
    lastMove[1]=c;
    this.r=r;
    this.c=c;
    this.dim=dim;
    computeAdjMatrix(); // recalculate the number of moves left at each square
 
    start(); // start the game
}

// overload the constructor

public KtH(int dim){
    // this will start the game automatically in the upper left corner of the board
    this(dim,0,0); // this calls the previous constructor
}
// default constructor follows
public KtH() {
    this(8); // this calls the constructor above
    }
private void start(){
    // note the first move has been made prior to entering start
    for (int i=1; i<adj[0].length * adj[0].length; i++) // this will step thru all the moves
      adj=(int)(Math.Random()*7)



 if (!nextMove())
           {
           System.out.println("game aborted for start position " + "("+ r+ ","+ c+ ")");
           System.out.println("the number of moves was " + ctr);
           break;
           }
if (nextMove==64)

    b.printBoard();
else 
System.out.println(" no board ");
  
}

private void  computeAdjMatrix(){
  
    // start with a nested for loop that runs thru all rows and cols
  
    for (int i=0; i<adj[0].length; i++)
        for (int j=0; j<adj[0].length; j++)
            adj[i][j]=numberOfMoves(i,j); // pass the row and col to the method
  
}

private int numberOfMoves(int r, int c){
    int ctr=0;
    if (b.getElement(r, c)!=0)
        return 0; // if the square in question was visited then return 0
    // compute the number of legal moves between 0 and 8
    // a simple for loop running thru the 8 possible legal moves
  
    for (int i=0; i<8; i++) // step thru the moves
        if (legal(r,c, i)==true )
            ctr++;
  
    return ctr;
              
}
private boolean legal(int r, int c, int m)
{
// (r,c) is position and m is the mth move
// return true if a legal move
// m must be between 0 and 7   

if (((r + v[m])> dim-1) || ( r+v[m]<0))
    return false; // off the board

if (((c + h[m])> dim-1) || ( c+h[m]<0))
    return false; // off the board
  
if (b.getElement(r + v[m], c + h[m])>0)
    return false;
  
return true;
}
private boolean nextMove(){
    // use the heuristic to find the next move
    // which is the legal move with the lowest adjacency matrix value
    // in case of a tie, simply pick the first of the moves
   
    int small=8; // larger than any possible adj matrix value
    int move=100; // an impossible move value
   
    for (int i=0; i<8; i++)
        if (legal(lastMove[0],lastMove[1],i)) // is this a legal square?
               if (adj[lastMove[0]+ v[i]][lastMove[1]+h[i]] < small)
               {move = i;
                 small=adj[lastMove[0]+ v[i]][lastMove[1]+h[i]];
               }
   
    if (move<8) // we found a move to make
        // make the move
    {int r=lastMove[0]+ v[move];
      int c=lastMove[1]+ h[move];
    b.setElement(r, c, ++ctr); // set the board at position (r,c) to 1
    lastMove[0]=r;
    lastMove[1]=c;
    computeAdjMatrix();
    return true;
    }
    else
        return false;
}
public static void main(String args[]){
    int r,c;
    KtH h;
    int dim=8;
    for (r=0; r<dim; r++)
        for ( c=0; c<dim; c++)
            h=new KtH(dim,r,c); // begin the tour of an 8 by 8 board in lower right corner
           
   
}
}

i modify the the start method instead of giving the number in sequence it will random some the sequence number, but other two questions im not sure about it

[fred rosenberger]

Hello and welcome to the ranch.

My guess is you won't get much help with a post like that. You may want to take a few minutes and read our HowToAskQuestionsOnJavaRanch FAQ. Generally speaking, broad questions don't get near the help of specific, focused questions.

Your post basically reads as "Please do my homework for me", which most folks find off-putting - especially with over 200 lines of code. Kudos on using code tags on your first post - that does help a LOT, but I think your question is a little broad.

[Andres John]

fred rosenberger wrote:Hello and welcome to the ranch.

My guess is you won't get much help with a post like that. You may want to take a few minutes and read our HowToAskQuestionsOnJavaRanch FAQ. Generally speaking, broad questions don't get near the help of specific, focused questions.

Your post basically reads as "Please do my homework for me", which most folks find off-putting - especially with over 200 lines of code. Kudos on using code tags on your first post - that does help a LOT, but I think your question is a little broad.

i already what it said in HowToAskQuestionsOnJavaRanch thank for the link
it my first time using the this link

[fred rosenberger]

Andres John wrote:i already what it said in HowToAskQuestionsOnJavaRanch thank for the link
it my first time using the this link

I understand that you are new. I'm trying to help you get a better experience here. I'm trying to give you hints on what you can do to get the help you need. Folks here will give you an AMAZING amount of help...but only if you make it possible for them to do so.

[William P O'Sullivan]

If this is a school or educational assignment, no one will do it for you.

At least lay out how you would attempt to code this by designing on paper or at least in your head!

WP

[Andres John]

this kind of project its knight's tour that do not use recursive but back tracking.

[Andres John]

William P O'Sullivan wrote:If this is a school or educational assignment, no one will do it for you.

At least lay out how you would attempt to code this by designing on paper or at least in your head!

WP

that what i'm trying to do, so i just think what the prof mean by this kind of question, and this is a knight's out which a complex problem, yet require a lot of thinking and algorithm

[Andres John]

Andres John wrote:the prof is asking me to do this
Create an alternate KtR that solves knight's tour problem for an 8 by 8 board by randomly picking a move from 0 to 7 and if legal make the move. If not legal, try doing this 100 times and if no legal moves after 100 tries abort the game as a failure.
If you make 64 moves print the board.

package arr;

import javax.swing.JOptionPane;

public class KtH {
private Board b;
private int ctr=0; // this counts the moves the knight makes
private int [] lastMove=new int[2]; // we need a 1 x 2 array to store (x,y) the pos. of last move
private int h[]={-2,-2,-1,-1,1,1,2,2}; // this is the change in column
private int v[]={-1,1,2,-2,2,-2,1,-1}; // this is change in row
private int adj[][]; // adjacency matrix keeping track of # of moves left from every square on board b
private int r,c,dim;


public KtH(int dim, int r, int c){
    adj=new int [dim][dim];
    b=new Board(dim); // instantiate a Board object b to dimension dim x dim
    b.setElement(r, c, ++ctr); // set the board at position (r,c) to 1
    lastMove[0]=r;
    lastMove[1]=c;
    this.r=r;
    this.c=c;
    this.dim=dim;
    computeAdjMatrix(); // recalculate the number of moves left at each square
 
    start(); // start the game
}

// overload the constructor

public KtH(int dim){
    // this will start the game automatically in the upper left corner of the board
    this(dim,0,0); // this calls the previous constructor
}
// default constructor follows
public KtH() {
    this(8); // this calls the constructor above
    }
private void start(){
    // note the first move has been made prior to entering start
    for (int i=1; i<adj[0].length * adj[0].length; i++) // this will step thru all the moves
      r=(int)(Math.Random()*8)
      c=(int)(Math.Random()*8)


 if (!nextMove())
           {
           System.out.println("game aborted for start position " + "("+ r+ ","+ c+ ")");
           System.out.println("the number of moves was " + ctr);
           break;
           }
else {

            for ( int j = 0; j < 7 && adj; j++ ) {

               adj = ++adj % 8;

               r = d+ [adj ];
              dim = c + h[ [adj  ];

             ctr = validMove( dim, dim );
               if (nextMove() ) {

                  r = dim;
                  c = dim;
                  board[dim][dim ] = ++moveNumber;
               }

         if ( adj== 64 )

 

      
  
}

private void  computeAdjMatrix(){
  
    // start with a nested for loop that runs thru all rows and cols
  
    for (int i=0; i<adj[0].length; i++)
        for (int j=0; j<adj[0].length; j++)
            adj[i][j]=numberOfMoves(i,j); // pass the row and col to the method
  
}

private int numberOfMoves(int r, int c){
    int ctr=0;
    if (b.getElement(r, c)!=0)
        return 0; // if the square in question was visited then return 0
    // compute the number of legal moves between 0 and 8
    // a simple for loop running thru the 8 possible legal moves
  
    for (int i=0; i<8; i++) // step thru the moves
        if (legal(r,c, i)==true )
            ctr++;
  
    return ctr;
              
}
private boolean legal(int r, int c, int m)
{
// (r,c) is position and m is the mth move
// return true if a legal move
// m must be between 0 and 7   

if (((r + v[m])> dim-1) || ( r+v[m]<0))
    return false; // off the board

if (((c + h[m])> dim-1) || ( c+h[m]<0))
    return false; // off the board
  
if (b.getElement(r + v[m], c + h[m])>0)
    return false;
  
return true;
}
private boolean nextMove(){
    // use the heuristic to find the next move
    // which is the legal move with the lowest adjacency matrix value
    // in case of a tie, simply pick the first of the moves
   
    int small=8; // larger than any possible adj matrix value
    int move=100; // an impossible move value
   
    for (int i=0; i<8; i++)
        if (legal(lastMove[0],lastMove[1],i)) // is this a legal square?
               if (adj[lastMove[0]+ v[i]][lastMove[1]+h[i]] < small)
               {move = i;
                 small=adj[lastMove[0]+ v[i]][lastMove[1]+h[i]];
               }
   
    if (move<8) // we found a move to make
        // make the move
    {int r=lastMove[0]+ v[move];
      int c=lastMove[1]+ h[move];
    b.setElement(r, c, ++ctr); // set the board at position (r,c) to 1
    lastMove[0]=r;
    lastMove[1]=c;
    computeAdjMatrix();
    return true;
    }
    else
        return false;
}
public static void main(String args[]){
    int r,c;
    KtH h;
    int dim=8;
    for (r=0; r<dim; r++)
        for ( c=0; c<dim; c++)
            h=new KtH(dim,r,c); // begin the tour of an 8 by 8 board in lower right corner
           
   
}
}

i modify the the start method instead of giving the number in sequence it will random some the sequence number, but other two questions im not sure about it

[Andres John]

import  static java.lang.Math.random;
public class KtH {
private Board b;
private int ctr=0; // this counts the moves the knight makes
private int [] lastMove=new int[2]; // we need a 1 x 2 array to store (x,y) the pos. of last move
private int h[]={-2,-2,-1,-1,1,1,2,2}; // this is the change in column
private int v[]={-1,1,2,-2,2,-2,1,-1}; // this is change in row
private int adj[][]; // adjacency matrix keeping track of # of moves left from every square on board b
private int r,c,dim;


public KtH(int dim, int r, int c){
    adj=new int [dim][dim];
    b=new Board(dim); // instantiate a Board object b to dimension dim x dim
    b.setElement(r, c, ++ctr); // set the board at position (r,c) to 1
    lastMove[0]=r;
    lastMove[1]=c;
    this.r=r;
    this.c=c;
    this.dim=dim;
    computeAdjMatrix(); // recalculate the number of moves left at each square
    r=(int)(random ()*8);
    c=(int)(random ()*8);
    start(); // start the game
}

// overload the constructor

public KtH(int dim){
    // this will start the game automatically in the upper left corner of the board
    this(dim,0,0); // this calls the previous constructor
}
// default constructor follows
public KtH() {
    this(8); // this calls the constructor above
    }
private void start(){
    // note the first move has been made prior to entering start
    for (int i=1; i<adj[0].length * adj[0].length; i++) // this will step thru all the moves
       if (!nextMove())
           {
    	   ctr=(int)(random()*8);
           System.out.println("game aborted for start position " + "("+ r+ ","+ c+ ")");
           System.out.println("the number of moves was " + ctr); 
           break;}
       else {
    	   for (int c=0; c<7; c++)
    		   ctr= ++ctr %8;
    	    	
    	    }
       }
    	   
    //b.printBoard(); 


private void  computeAdjMatrix(){
   
    // start with a nested for loop that runs thru all rows and cols
   
    for (int i=0; i<adj[0].length; i++)
        for (int j=0; j<adj[0].length; j++)
            adj[i][j]=numberOfMoves(i,j); // pass the row and col to the method
   
}

private int numberOfMoves(int r, int c){
    int ctr=0;
    if (b.getElement(r, c)!=0)
        return 0; // if the square in question was visited then return 0
    // compute the number of legal moves between 0 and 8
    // a simple for loop running thru the 8 possible legal moves
   
    for (int i=0; i<8; i++) // step thru the moves
        if (legal(r,c, i)==true )
            ctr++;
   
    return ctr;
               
}
private boolean legal(int r, int c, int m)
{
// (r,c) is position and m is the mth move
// return true if a legal move
// m must be between 0 and 7    

if (((r + v[m])> dim-1) || ( r+v[m]<0))
    return false; // off the board

if (((c + h[m])> dim-1) || ( c+h[m]<0))
    return false; // off the board
   
if (b.getElement(r + v[m], c + h[m])>0)
    return false;
   if  (((c + h[m])==64) || ( c+h[m]==64))
return true;
   else 
	   System.out.print(" ");
}
private boolean nextMove(){
    // use the heuristic to find the next move
    // which is the legal move with the lowest adjacency matrix value
    // in case of a tie, simply pick the first of the moves
    
    int small=8; // larger than any possible adj matrix value
    int move=7; // an impossible move value
    
    for (int i=0; i<8; i++)
        if (legal(lastMove[0],lastMove[1],i)) // is this a legal square?
               if (adj[lastMove[0]+ v[i]][lastMove[1]+h[i]] < small)
               {move = i;
                 small=adj[lastMove[0]+ v[i]][lastMove[1]+h[i]];
               }
    
    if (move<8) // we found a move to make
        // make the move
    {int r=lastMove[0]+ v[move];
      int c=lastMove[1]+ h[move];
    b.setElement(r, c, ++ctr); // set the board at position (r,c) to 1
    lastMove[0]=r;
    lastMove[1]=c;
    computeAdjMatrix(); 
    return true;
    }
    else
        return false;
}
public static void main(String args[]){
    // ask user for starting position
    // int r=Integer.parseInt(JOptionPane.showInputDialog("enter the row"));
//    int c=Integer.parseInt(JOptionPane.showInputDialog("enter the col"));
    int r,c;
    KtH h;
    int dim=100;
    for (r=0; r<dim; r++)
        for ( c=0; c<dim; c++)
            h=new KtH(dim,r,c); // begin the tour of an 8 by 8 board in lower right corner
   
}
}

can't get the ideas of t 64 move

[Andres John]

I will end this boring and hard java program that nobody could help me :C

import javax.swing.JOptionPane;

}



private void start(){

int moves = 0;
int failed=0;

while (moves<dim*dim){

if (!nextMove())
	
{  
	if (moves>dim*dim-4)
		System.out.println("there are "+ moves +" in the " + failed + " number of tries");
	moves=0;
	failed++;
	b.resetBoard();
	// remake the first move
	ctr=0;
	b.setElement(r, c, ++ctr); // set the board at position (r,c) to 1

	lastMove[0]=r;

	lastMove[1]=c;
	
}

moves++;

}

 b.printBoard();
}
private boolean legal(int r, int c, int m)

{

// (r,c) is position and m is the mth move




if (((r + v[m])> dim-1) || ( r+v[m]<0))

    return false; // off the board


if (((c + h[m])> dim-1) || ( c+h[m]<0))

    return false;

   

if (b.getElement(r + v[m], c + h[m])>0)

    return false;

return true;

}

private boolean nextMove(){

int r=lastMove[0];

int c=lastMove[1];

int tries = 0;

while (tries<=64){

int random = (int)(Math.random()* 8 + 0);    

if (legal(r, c, random)){


b.setElement(r + (v[random]), c + (h[random]), ++ctr);	

lastMove[0]=r + (v[random]);

lastMove[1]=c + (h[random]);

return true;

}

tries++;

}

return false; // couldn't find a legal move in 50 random tries

   

}

KtHRandom h;


    h=new KtHRandom(8,7,3);
}

}

here it the final result now it over, game over Happy !!

[Jeff Verdegan]

Andres John wrote:I will end this boring and hard java program that nobody could help me :C

There are plenty of people here who could have helped you. You just didn't ask a clear question that would have made it easy for people to understand what your problem is.