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Symmetric matrix Write a static method which takes a 2-dimensional array of type

ID: 3565745 • Letter: S

Question

Symmetric matrix

Write a static method which takes a 2-dimensional array of type int, which represents a matrix, as its argument, and returns true if the matrix is symmetric and false otherwise. A matrix is symmetric if the entry at row i and column j is the same as the entry at row j and column i for each i and j. The diagonal entries (i.e. entries with the same row and column) can be any number.

Write a driver file to test your method. It should call your method with at least three different inputs.

Explanation / Answer

public class SymmetricMatrix
{
    public static void main(String args[ ])
    {
        int i, j, flag = 0;
        int matrixArgument1[][]= new int[][]{
{ 1, 2, 3},
{ 2, 1, 2},
{ 3, 4, 3}};
      
    int matrixArgument2[][]= new int[][]{
{ 1, 2, 3},
{ 9, 1, 2},
{ 3, 4, 9}};
      
int matrixArgument3[][]= new int[][]{
{ 1, 2, 3},
{ 9, 1, 4},
{ 3, 6, 9}};
        System.out.println(" Matrix 1 is : ");
        print(matrixArgument1);
        checkSymmetric(matrixArgument1);
        System.out.println(" Matrix 2 is : ");
        print(matrixArgument2);
        checkSymmetric(matrixArgument2);
        System.out.println(" Matrix 3 is : ");
        print(matrixArgument3);
        checkSymmetric(matrixArgument3);

      
    }
  
    public static void print(int matrix[][]){
      
        for (int i=0;i<3;i++)
        {
             for(int j=0;j<3;j++)
            System.out.print(" "+matrix[i][j]+" ");
             System.out.println();
        }
    }
    public static void checkSymmetric(int matrix[][]){
     int flag=0;
        for (int i=0;i<3;i++)
            for(int j=0;j<3;j++)
                  if (matrix[i][j] != matrix[j][i])
                        flag = 1;

        if (flag == 1)
                 System.out.println(" Matrix is not symmetric");
        else
                  System.out.println(" Matrix is symmetric");
    }
}


****************Sample Output******************************

Compiling the source code....
$javac SymmetricMatrix.java 2>&1

Executing the program....
$java -Xmx128M -Xms16M SymmetricMatrix