Magic Square

batman3280 · #1 27-Feb-2006, 12:14

Hi
I am new to this forum but i knew that every body is helpful
i have trouble with my assignment
i need to write a program that implemnt a magic square 3x3 and 4x4
but i do not know how this algorithm work
my i have any help with this
i have the following algorithm

JAVA Code:

import javax.*;

public class MaicSquare
{
	
	public static void main(String args[])
	
	
	
	{
		int r= 0; int c= 0; int i; int size= b.length;
		
		
		// Make up the magic square 
        
        r= 0; c= size/2; i= 1; 
	
		while (b[r][c] == 0)
 { 
		b[r][c]= i; i= i+1; 

			if (b[mod(r-1, size)][mod(c+1, size)] == 0)
							
				{ 
				r= mod(r-1, size); 
				c= mod(c+1, size); 
				
				
				
				} 
					else 
					
				r= mod(r+1,size); 
				
} 
 	
	}
	
		
}

TreyAU21 · #2 27-Feb-2006, 14:07

Can you elaborate a little more as to what this "magic square" is? (And describe further the functionality required)

Also, it helps to put the JAVA tags around your code to properly format the code and highlight key words, etc. ([java] is the tag.)

batman3280 · #3 02-Mar-2006, 12:48

This code suppose to generate Magic square NxN but i could not run for 3X3

JAVA Code:

import java.awt.*;

public class T2 {
static	int N,x1,y,i,Count;static int c=0; static int total;
static int matrix[][]=new int[3][3];
static boolean flag[]=new boolean [20];
static	int x[]=new int [20];
static   int solution[] =new int [20];


	public static void main(String args[])
	{
	
 Count=0;int v=0;
//false};
flag[0]=false;
boolean res;
for(int i=1;i<10;i++)
      { 
         x[i]=0;
        
         
       flag[i]=false;
        }
        
		Permutation(3);	
		
	
			
		// the single dimension matrix is transformed into a 2D one
		
		for(x1=0; x1<3; x1++)
		{
			
		
		for( y=0; y<3; y++)
		 {
			
		matrix[x1][y] = solution[c];
		c++;
       System.out.print("\t" + matrix[x1][y] + " ");
      
			} 
			
			
			
			System.out.println("  \n");      

			
		}
		
		
		
	//	res=Test_Magic();
		System.out.println("  \n");      


}




static void Permutation(int count)
{ 
	if(count == 9)
	{
	
      printSolution();
      
      
     }
      else	
          
       for( i=1;i<9;i++)
        {
       
                 
           if (x[i]==0) 
            { 
           
             //System.out.print(count + " " );
             
             x[i]=1;//mark as visited 
             
             solution[count]=i;
                   
             
                      	
           	if (R() == 15) 
               
                { System.out.print(R());
                 if (count<9 )
                   
                   Permutation(count+1);
                else 
                
                  // at the end 
                Test_Magic() ;
                } 
             
   
               
                
             
           
             
             
             
             }
             else 
             
              Permutation(count+1);
             
              x[i]=0;
             
             
             
        
}}


  static  void printSolution()
   
   
 {
 	
 	System.out.println("");
 	
 	
 } 
 
 public static int R()
 { int n=3;int total=0;
 
 for(x1=0;x1<3;i++)
			{
	        total=0;
	         for(int y=0;y<3;y++)
	        
	         total+=matrix[y][x1];
	       if (total!= n*(n*n+1)/2);
	    	return total;  
	        }
	        
	        System.out.print(total);
	        return total;}
 
 	public static boolean Test_Magic()
	{
		int total =0;
	   	int n=3;
		// first check if the rows are summmed equally
		
			for(x1=0;x1<3;i++)
			{
	        total=0;
	         for(int y=0;y<3;y++)
	        
	         total+=matrix[y][x1];
	       if (total!= n*(n*n+1)/2);
	    	return false;  
	        }
     
		// second check if the columns are summed equally

	for( x1=0;x1<n;x1++){
	    total=0;
	    for( y=0;y<n;y++)
	        total+=matrix[x1][y];
	        
	        
	    if (total != n*(n*n+1)/2);
	    	return false;
	    	
	    	  }
	   
	for( y=0;y<n;y++){
	
	    total+=matrix[y][y];
	if (total != n*(n*n+1)/2);
	    return false;}
	   
	    
	  	//the other diagonal
    total=0;{
    
	for(int y=0;y<n;y++)
	   total+=matrix[y][n-1-y];
	  if (total != n*(n*n+1)/2);
	     return false;
	     
	      }
       //return true;
	   

		}
		
		
	 public	static  void shufflePermutation() {
        int temp,location;
    	for( i=9;i>1;i--){
    	    location=x[i];//(int)(Math.random()*i);
    	    temp = solution[location];
    	    solution[location] = solution[i-1];
    	    solution[i-1] = temp;
    	}
    }
	
	
	
	
	
 
 	


 
}//end of the main class

TreyAU21 · #4 02-Mar-2006, 14:53

There are several parts of this code that stick out to me as faulty or not needed. There are also several parts where I don't really know what you are trying to do. If you are wanting help from this board... the best thing that you could do is to comment your code really well.

Other conventions that help us read and understand the code better besides commenting well are:
1.) Better use of whitespace
2.) Name variables better. The name needs to represent it's function in the code. Particularly avoid names such as N,x1,y,i, and c. Also overly generic names such as solution and flag can often be confusing to someone who isn't familiar with the code.

Some things that immediately stuck out with this code:

You don't use anything from java.awt.*, so there really isn't any need to import it. Unless you are planning to make this program graphical later:

JAVA Code:

import java.awt.*;

This jumbling mess of global variables should be cleaned up. Although Java (and most languages) allow multiple variable initializations on a single line... it isn't really good coding necessarily. Just give each variable a line for itself. Also in your example, all of the loop counters don't need to be global.

JAVA Code:

public class T2 {
static int N,x1,y,i,Count;static int c=0; static int total;
static int matrix[][]=new int[3][3];
static boolean flag[]=new boolean [20];
static int x[]=new int [20];
static int solution[] =new int [20];

Also, I noticed that most of your arrays... although they will be holding only 9 items... you initialized them to hold 20 items? This has to do with the way you are initializing your index counter in the arrays. You are starting with a counter value of 1. '1' is actually the 2nd element in an array (with 0 being the first). You should start your counter at 0 and initialize your array as holding 9 elements.

JAVA Code:

for(int i=1;i<10;i++) { 
   x[i]=0;
   flag[i]=false;
}

There's actually a lot of areas of this program that should be improved upon, so if you can provide comments for each area... we could take it one section at a time... and try to get this thing working.

Oh and please put the [java] tags around your code

... Thanks.

batman3280 · #5 03-Mar-2006, 01:20

thank so much for your reply i will tell what i should

i should generate magic square of NxN using Brute Force algorithm
my number should be generated using Permutation but the problem i got that my Permutation method generate numbers from 1 to 8 when i want to have the matrix of 3 that way i have stick n to 3 explicty the N shluld be any number entered by the user that mean i should initialize the array according to the user input that's why you see single array initialized to 20 because i was testing for 4x4
The second problem that i could not reorder the content of the array to meet the magic square reule that they should equal (N^2+1)*N/2

this checked in the inner loop of the Permutation method
the rule of Permutation states that i should start my Permutation with one
i am trying to implement simple magic square ; i have taken this algorithm from this website personal.vsnl.com
personal.vsnl.com
personal.vsnl.com
this what i am trying to do the Global variable i am trying to declear because i want to use the same value

JAVA Code:

public class T2 {


static int matrix[][]=new int[3][3];//this should be of size NxN 
// and want to access it for the whole program ohterwiase it gives error

static	int x[]=new int [20];//this also should N//i am using it for checking  
static  int solution[] =new int [9];
//This also should be of Size N


	public static void main(String args[])
	{
	
	int total;	
		
     int c=0;
 
   for(int i=0;i<10;i++)
      
         x[i]=0;
        
         
       // i should as the user about the size of the array 
     
        
		Permutation(1);// if i use Permutation of 3 i get stack over flow even the concept of Permutation is to         
                                            //startwith 1	
		
	
			
		// the single dimension matrix is transformed into a 2D one
		
		for(int x1=0; x1<3; x1++)
		{
			
		
		for( int y=0; y<3; y++)
		 {
			
		matrix[x1][y] = solution[c];
		c++;
       System.out.print("\t" + matrix[x1][y] + " ");
      
			} 
			
			
			
			System.out.println("  \n");      

			
		}
		
		
		
	//	res=Test_Magic();
		System.out.println("  \n");      


}


//this method should generate the combinatin of numbers 

static void Permutation(int count)
{ 


// here i should generate the matrix according to the input 
//if it is of size 3 i should Permutate 9 ,4 should 16 and exc..
//the 9 should obtain from nxn
	if(count == 9)
	{
	
      printSolution();
      
      
     }
      else	
       //the for loop in general should be 
       //for( int i=1;i<n*n;i++)
       // 
          
       for( int i=1;i<9;i++)
        {
       
            //check if i did not visit this cell      
           if (x[i]==0) 
            { 
           
             //System.out.print(count + " " );
             
             x[i]=1;//mark as visited 
             
             solution[count]=i;
                   
             //here i should generate the combanition 
               if (count<9 )
                   
                   Permutation(count+1);
               
             
             
             
             
             }
             else 
                Permutation(count+1);
              Test_Magic();//to see if the row of each sum are equalyl 
              //but i have a problem checking it with permutation 
              //and reorder the number 
             
              x[i]=0;
             
             
             
        
}}


  static  void printSolution()
   
   
 {
 	
 	System.out.println("");
 	
 	
 } 
 
 
 
 	public static boolean Test_Magic()
	{
		int total =0;
	   	int n=3;
		// first check if the rows are summmed equally
		
			for(int x1=0;x1<3;x1++)
			{
	        total=0;
	         for(int y=0;y<3;y++)
	        
	         total+=matrix[y][x1];
	       if (total!= n*(n*n+1)/2);
	    	return false;  
	        }
     
		// second check if the columns are summed equally

	for( int x1=0;x1<n;x1++){
	    total=0;
	    for( int y=0;y<n;y++)
	        total+=matrix[x1][y];
	        
	        
	    if (total != n*(n*n+1)/2);
	    	return false;
	    	
	    	  }
	   
	for( int y=0;y<n;y++){
	
	    total+=matrix[y][y];
	if (total != n*(n*n+1)/2);
	    return false;}
	   
	    
	  	//the other diagonal
    total=0;{
    
	for(int y=0;y<n;y++)
	   total+=matrix[y][n-1-y];
	  if (total != n*(n*n+1)/2);
	     return false;
	     
	      }
       //return true;
	   

		}
		
		
	 
	
	
 
 	


 
}//end of the main class

this the Code again but when i remove the Global Varuable i did not get any output you can run it if you have a Jcreator
i will be so glad if you can figer what is wrong with my code i have spent 4 days before i subscibe to your forum i have given you the url to kknow what i am trying to do; so do not get upset that i might waste your time ,but may be i understand wrong but i want to implement it using this alogorithm
thank you for your attantion this code driving me crazy

batman3280 · #6 03-Mar-2006, 13:44

hi
i have generate the code for 3x3 but when i tried for 4x4 it did not run here is the working version Try it with 3 it works perfectly but with 4 it did not work

JAVA Code:

// This is the tester class


public class Tester
{  static int N=4;
static	boolean flag[]=new boolean[N*N];

static   int solution[]=new int[N*N];
static	int count=0;
// method to fill in the matrix with values of numbers from 1toN^2
	


  static void fill_square(int count, int N)
   {
   	  	  
   	  int x[] = new int[N*N];
   	  // fill in X
   	  for(int i=0; i<N*N; i++)
   	     x[i] = i+1;
      
      if(count==N)
      
     { if(Test_Magic(solution,4) == true)
      
         
         	PrintMagicSquare(solution, 4);
         	
         	
      }
                 
       else
       
       for(int i=0;i<N;i++)
         
         if (flag[i]==false)
         { 
            flag[i]=true;
            
            solution[count]=x[i];
            fill_square(count+1, N);
         
             flag[i]=false;
         	  break;
       }     
         
   	   
   }	
	
	
	public static boolean Test_Magic(int[] init_matrix, int n)
	{
		
		int total =0;
		int x,y;
		int i =0;
		int [][] matrix = new int[n][n];
		
		// the single dimension matrix is transformed into a 2D one
		
		for(x=0; x<n; x++)
		{
			for(y=0; y<n; y++)
			{
				matrix[x][y] = init_matrix[i];
				i++;
			}
		}
		
		
		
		// first check if the rows are summmed equally
		
		
		
		for(x=0; x<n; x++)
		{
			for(y=0; y<n; y++)
			{
				total += matrix[x][y];
			}
			
			if(total != (((n*n*n)+n)/2))
			return false;
			
			else 
			total =0;		// reset the total to try for the next row
			
		}

	
	// second check if the columns are summed equally
	

	total =0; 
	
	for(y=0; y<n; y++)
	{
		
		for(x=0; x<n; x++)
		{
			total += matrix[x][y];
		}
		
		if(total !=(((n*n*n)+n)/2))
		return false;
		
		total =0;
	}
	
	
	
	// third we check if the diagonals are summed equally
	
	total =0;
	// we have only one loop that goes through the rows
	
	for(x=0; x<n; x++)
	{
		total += matrix[x][x];  // since the diagonals are at (0,0), (1,1), (2,2)...etc
	}
	
	if(total != (((n*n*n)+n)/2))
	
	return false;
	
	
	// when all checks are complete....
	
	return true;
	
	
	
		}
		
	// method to print the magic sqaure	
		
   public static void print_square (int [] matrix)
   {
   	  for(int x=0; x<matrix.length; x++)
   	  System.out.println(matrix[x]);
   	  	
   	
   	
   }
   /////////////////////////////////////////////
   
   static void PrintMagicSquare(int[]init_matrix,int N)
{   int i=0;
    int matrix[][]=new int[N][N];
  	for(int x=0; x<N; x++)
		{
			for(int y=0; y<N; y++)
			{
				matrix[x][y] = init_matrix[i];
				i++;
			}
		}
  
  
  for (int k=0; k<N; k++) 
  {
    for (int j=0; j<N; j++)
    System.out.print(" " +  matrix[k][j] + " " );

    System.out.print("\n");
  }

  System.out.print("\n\n");
}
	
   
   /////////////////////////////////////////////
	
	
	
	
	public static void main (String args[])
	{
		
		int i=0;
		int init_matrix [] = new int [16];
		int matrix[][] = new int [4][4];

	
	PrintMagicSquare(init_matrix, 4);
		
		
		System.out.println(Test_Magic(init_matrix,4));
		
		fill_square(0, 15);
	
	
		
	
	
	}
	
}

TreyAU21 · #7 03-Mar-2006, 16:17

One of the problems with your program is organization... hopefully you understand objects in Java, because the following code implements your code using objects. I still haven't done the "magic" part of your project, but to be able to fully understand what's going on... you need to be organized first.

This Driver file asks the user for the number of rows, and then creates a Board object for that specific number of rows. It then permutates the board and prints the board:

JAVA Code:

   import java.io.*;
    
    public class magicSquares {
    	
       public static void main(String[] args) {
         BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
         Board board; 	//Stores the Magic Sqares Board
         int numOfRows; //Stores user input num of rows/columns
      	
      	// This loops until the user inputs a proper value
         while(true) {
            System.out.print("Please enter the number of rows/column (3-10): ");
            try {
               numOfRows = Integer.parseInt(in.readLine()); 
               if (numOfRows >= 3 && numOfRows <= 10) { //Input check
                  break; }
               System.out.println("ERROR: Number Out of Range... Value must be between 3 and 10");
            }
                catch (Exception ex) { System.out.println("ERROR: Invalid Input... Try Again"); }}
                
         
         board = new Board(numOfRows);   // Initialize board with specific numOfRows
         board.permutate();   // Do what needs to be done here	
         System.out.println(board.print());   // Print out the board
      	
      }
   }

This is the Board object class. Notice how much cleaner and extendable it is. You could theoretically create a board of 3x3, 4x4, .... nxn (memory withstanding). There are no numbers that are hard coded, it is all based on the user's input and flexible to what they enter (in my example, I limit the input to between 3-10 for display purposes)

JAVA Code:

public class Board {
    	
      private int boardArray[][];
      private int numOfRows;
   	
       public Board() {
         numOfRows = 3; //Default to a 3x3 board
         boardArray = new int[numOfRows][numOfRows];
      }
      
       public Board(int rows) {
         numOfRows = rows;
         boardArray = new int[numOfRows][numOfRows];
      }
      
       public void permutate() {
        // Do the Magic
      }
      
       public String print() {
         String result = "";
         for(int i=0; i<getNumOfRows(); i++) {
            for(int j=0; j<getNumOfRows(); j++) 
               result += boardArray[j][i] + "\t";
            result += "\n";
         }
         return result;
      }
      
   	// Getter Functions
       public int getNumOfRows() {
         return numOfRows;
      }
      
   }

It's all about organization... once you have the structure down... you can more easily complete the more complex features.

Now try to get your program working using this structure if you like. If you need more halp on the permutate part, I need some more details. Correct me if I'm wrong... but you need to figure out how to insert the numbers in the squares such that the sum of the values in each row are equal... and the sum of the values in each column are equal?

batman3280 · #8 07-Mar-2006, 09:25

hello Troy
Thank you for your help in this problem . if do not mind i would like to know if you have any experince with multithreading program and coding because i am taking an operating cource and i don not understand how threads behave in term of passing signals ,wait for siganl so if you could help i will be glad for that . also i want to learn how do you learn the indent in coding any Programming language
Thanx

bts · #9 29-Nov-2007, 02:57

this method for generate magic for any number(odd number and even number).But I 'm not sure why I can't run this code,please check method of calculate.....

[]constructor
[]generate()

JAVA Code:

MagicSquare(int number){
         this.number = (int) Math.sqrt(number);
         magicArray = new int[this.number][];
     for (int i = 0; i < this.number;i++) {
          magicArray[i] = new int[this.number];
     }
     generateMagic();
     }
     private void generateMagic() {
         if(this.number % 2 != 0){
             int i = (this.number+1)/2;
             int j = (this.number-1)/2;
             int max=1;
             while(max<=Math.pow(this.number,2)){
                 magicArray[i][j]=max;
                 i++;
                 j++;
                 if(max % this.number == 0){
                     i++;
                     j--;
                 }
                 max++;
                 if(i>=this.number)
                     i-=this.number;
                 if(j>=this.number)
                     j-=this.number;
             }
         }
         if(this.number % 4 == 0){
             int i=0;
             int j=this.number-1;
             int max=1;
             while(i<this.number){
                 if(i%4==0||i%4==3){
                     if(j%4==0||j%4==3){
                         magicArray[i][j]=max;
                         max++;
                     }
                     else{
                         magicArray[i][j]=(int)Math.pow(this.number,2)-max+1;
                         max++;
                     }
                 }
                 else{
                     if(j%4==0||j%4==3){
                         magicArray[i][j]=(int)Math.pow(this.number,2)-max+1;
                         max++;
                     }
                     else{
                         magicArray[i][j]=max;
                         max++;
                     }
                 }
                 j--;
                 if(j<0){
                     j=this.number-1;
                     i++;
                 }
             }
         }
         if(this.number % 4==2){
             int i=0;
             int j=this.number/2;
             int max=1;
             int count=0;
             while(max<=Math.pow(this.number,2)){
                 if(i<this.number/2){
                     if(i>=(this.number/2)-1 && j>=(this.number/2)-1 && j<(this.number/2)+1){
                         j--;
                         magicArray[i][j]=max;
                         max++;
                         i++;
                         magicArray[i][j]=max;
                         max++;
                         j++;
                         magicArray[i][j]=max;
                         max++;
                         i--;
                         magicArray[i][j]=max;
                     }
                     else{
                         magicArray[i][j]=max;
                         max++;
                         i++;
                         j--;
                         magicArray[i][j]=max;
                         max++;
                         j++;
                         magicArray[i][j]=max;
                         max++;
                         i--;
                         j--;
                         magicArray[i][j]=max;
                         j++;
                     }
                 }
                 else if(i<=(this.number/2)+2){
                     if(i>=(this.number/2)+1 && j>=(this.number/2)-1 && j<(this.number/2)+1){
                         magicArray[i][j]=max;
                         max++;
                         i++;
                         j--;
                         magicArray[i][j]=max;
                         max++;
                         j++;
                         magicArray[i][j]=max;
                         max++;
                         i--;
                         j--;
                         magicArray[i][j]=max;
                         j++;
                     }
                     else{
                         j--;
                         magicArray[i][j]=max;
                         max++;
                         i++;
                         magicArray[i][j]=max;
                         max++;
                         j++;
                         magicArray[i][j]=max;
                         max++;
                         i--;
                         magicArray[i][j]=max;
                     }
                 }
                 else{
                     j--;
                     magicArray[i][j]=max;
                     max++;
                     i++;
                     j++;
                     magicArray[i][j]=max;
                     max++;
                     j--;
                     magicArray[i][j]=max;
                     max++;
                     i--;
                     j++;
                     magicArray[i][j]=max;
                 }
                 max++;
                 i-=2;
                 j+=2;
                 count++;
                 if(count==this.number/2){
                     count=0;
                     i+=4;
                     j-=2;
                     if(i>=this.number)
                         i=1;
                     if(j<0)
                         j=this.number-2;
                 }
                 if(i<0)
                     i=this.number-2;
                 if(j>=this.number)
                     j=1;
             }
         }
     }

--------------------------------
thank you for your attantion this code
thanks...

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Rate This Thread
Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
OT: nth power square root math question	earachefl	C++ Forum	1	18-Feb-2006 08:45
Convert the input into square yards	pjpav	Java Forum	1	08-Oct-2005 08:43
morrowind - magic menu problem	gino	Computer Software Forum - Games	0	25-Sep-2005 11:19
Need help with my programs, please help.	agentxx04	C Programming Language	1	23-Sep-2004 19:02

Magic Square

Re: Magic Square

any help with this code Magic Square Please

Re: Magic Square

Re: Magic Square

Re: Magic Square

Re: Magic Square

Re: Magic Square

Re: Magic Square