Question

The following gives the backtracking algorithm in pseudo-code for a constraint satisfaction problem, where U is a set of unassigned variables, and A is the current partial assignment search(U,A) if (U) return A; remove a variable X from U; for (each value a in X's domain) if (X-a is consistent with A) add X=a to A; res - search(U,A) if res !# false return res remove X=a from A; return false; A magic square of size N is an N x N square grid filled with distinct numbers from 1 to N2 such that the numbers in each row, in each column, as wel as the numbers in the main and secondary diagonals, all add up to the same value. Based on the above algorithm, write a program in C++ or Java to find a 3 × 3 magic square

Answer 1

As per your requirement i have written code which fulfill all your requirements please follow it step by step.

import java.util.*;

import java.io.*;

class SquaresMatrixClass

{

int elementN;

int magicObject[][];

SquaresMatrixClass()

{

String filename = "nums.txt";

try

{

//Here we will create Scanner object to read from file

  

Scanner scannerObject= new Scanner(new File(filename));

  

//Actually here we will read first integer from file

elementN = scannerObject.nextInt();

magicObject = new int[elementN][elementN];

  

for(int w=0; w<elementN; w++)

for(int q=0; q<elementN; q++)

{

magicObject[w][q]=scannerObject.nextInt();

  

}

}

catch(Exception e)

{

System.out.println(e);

}

}

SquaresMatrixClass(int elementAObject[])

{

elementN= (int)Math.sqrt(elementAObject.length);

  

magicObject = new int[elementN][elementN];

  

int s=0;

  

for(int w=0;w<elementN;w++)

  

for(int q=0; q<elementN ;q++)

{

  

magicObject[w][q] = elementAObject[s];

s++;

}

}

int SumrightLeftDiagonal()

{

int elementSum=0;

  

for(int w=elementN-1;w>=0;w--)   

{

elementSum=elementSum+magicObject[w][elementN-1-w];

}

return elementSum;

}

int leftRightDiagonalSum()

{

int elementSum=0;

for(int w=elementN-1;w>=0;w--)   

{

elementSum=elementSum+magicObject[w][w];

}

return elementSum;

}

int Sumcolumn()

{

int elementSum=0;

for(int q=0;q<elementN;q++)

elementSum=elementSum+magicObject[0][q];

  

return elementSum;

}

int Sumrow()

{

int elementSum=0;

  

for(int q=0;q<elementN;q++)

  

elementSum=elementSum+magicObject[q][0];

  

return elementSum;

}

  

boolean correctnumber()

{

for(int w=0; w<elementN; w++)

for(int q=0; q<elementN;q++)

if(magicObject[w][q] < 1 || magicObject[w][q] > elementN*elementN) return false;

return true;

  

}

  

boolean validMagicSquare()

{

if(correctnumber() && Sumrow()==Sumcolumn() && Sumcolumn()== leftRightDiagonalSum() && leftRightDiagonalSum()== SumrightLeftDiagonal() ) return true;

  

else return false;

}

public String toString()

{

String stringContent="";

  

for(int w=0; w<elementN; w++)

{

for(int q=0; q<elementN; q++)

stringContent=stringContent+ magicObject[w][q]+" ";

stringContent=stringContent+"\elementN";

}

  

return stringContent;

}

}

public class MagicSquaresMatrix

{

public static void main(String elementAObject[])

{

SquaresMatrixClass matrixObject;

Scanner scannerObject= new Scanner(System.in);

int characterFlag=0;

while(characterFlag!=3)

{

  

System.out.println("1. Create Magic square from file ");

System.out.println("2. Create Magic square from input ");

System.out.println("3. Exit the program ");

characterFlag=scannerObject.nextInt();

if(characterFlag==1)

{

matrixObject= new SquaresMatrixClass();

System.out.println(matrixObject);

if(matrixObject.validMagicSquare())System.out.println("It is elementAObject magicObject Square ");

else System.out.println("It is not elementAObject magicObject Square ");

}

else if(characterFlag==2)

{

int elementN;

System.out.println("Enter size of square matrix");

elementN=scannerObject.nextInt();

int objectArray[] = new int[elementN*elementN];

  

System.out.println("Enter "+elementN*elementN+" elements ");

for(int w=0;w<elementN*elementN; w++)

objectArray[w]=scannerObject.nextInt();

matrixObject= new SquaresMatrixClass(objectArray);

System.out.println(matrixObject);

  

if(matrixObject.validMagicSquare())System.out.println("It is elementAObject magicObject Square ");

else System.out.println("It is not elementAObject magicObject Square ");

}

else if(characterFlag==3)

break;

}

}

}