Chapter 7, Problem 21E

Explanation of Solution

Method “isMagicSquare()” to return “true” if it is magic square:

//Definition of class Test

public class Test

{

    //Definition of main class

    public static void main(String[] args)

    {

        //Create two dimensional array

        int a[][] = { { 2,7,6 },

                { 9,5,1}, {4,3,8}};

        //Call the method transpose

        System.out.println(isMagicSquare(a));

    }

    //Definition of method isMagicSquare

    public static boolean isMagicSquare(int[][] a)

    {

        //check the condition

if (a.length == 0 || a.length == 1 && a[0].length == 1)

        {

            //Return the value true

            return true;  

        }

        //Assign the variable sum to "0"

        int sum = 0;

        //Traverse the loop till it reaches the length

        for (int c = 0; c < a[0].length; c++)

        {

            //Add the sum

            sum += a[0][c];

        }

        // Compute all row sums

        for (int r = 0; r < a.length; r++)

        {

            //Check the condition for not in square

            if (a[r].length != a.length) {

            //Return the value false

            return false;  

        }

        //Assign "rowSum" to "0"

        int rowSum = 0;

        //Traverse the loop till it reaches the length

        for (int c = 0; c < a[r].length; c++) {

            //Add the row values

            rowSum += a[r][c];

        }

        //Check whether the sum not equal to rowSum

        if (rowSum != sum) {

            //Return the value false

            return false;

        }

    }

    // Compute all column sums

    for (int c = 0; c < a...