ISC COMPUTER SCIENCE PRACTICAL 2016 QUESTION 2 : MATRIX

Question:

Write a program to declare a square matrix A[][] of order (M x M) where ‘M’ must be greater than 3 and less than 10. Allow the user to input positive integers into this matrix. Perform the following tasks on the matrix:

(a) Sort the non-boundary elements in ascending order using any standard sorting technique and rearrange them in the matrix.
(b) Calculate the sum of both the diagonals.
(c) Display the original matrix, rearranged matrix and only the diagonal elements of the rearranged matrix with their sum.

Example 1

INPUT :M = 4

9 2 1 5 
8 13 8 4 
15 6 3 11 
7 12 23 8 

OUTPUT:

ORIGINAL MATRIX

9 2 1 5 
8 13 8 4 
15 6 3 11 
7 12 23 8 

REARRANGED MATRIX

9 2 1 5 
8 3 6 4 
15 8 13 11 
7 12 23 8 

DIAGONAL ELEMENTS

9   5 
 3 6  
 8 13  
7   8  

SUM OF THE DIAGONAL ELEMENTS = 59

public class ISC2016Q2 {

       public static void main(String[] args) {

             int M;

             Scanner in = new Scanner(System.in);

             System.out.println("Enter the order of the matrix:");

             M = in.nextInt();

             while( M<=3 || M >= 10) {

                    System.out.println("INVALID INPUT,try again:");

                    M = in.nextInt();

             }

             Matrix obj = new Matrix(M);

             System.out.println("Enter the elements of the matrix:");

             obj.inputMatrix();

             System.out.println("ORIGINAL MATRIX:");

             obj.displayMatrix();

             System.out.println("REARRANGED MATRIX:");

             obj.rearangedMatrix();

             obj.displayMatrix();

             System.out.println("DIAGONAL ELEMENTS:");

             obj.displayDiagonalElements();

             in.close();

       }

}

class Matrix{

public void displayDiagonalElements() {

       for(int i=0;i<order;i++) {

             for(int j=0;j<order;j++)

                    if(i==j || i+j == order-1) {

                          System.out.print(Mat[i][j]+" "); sum_of_diagonals += Mat[i][j];}

                    else

                          System.out.print(" ");

             System.out.println();

             }

       System.out.println("SUM OF DIAGONAL ELEMENTS:"+sum_of_diagonals);

       }

public void rearangedMatrix() {

       int counter =0;

       for(int i=1;i<order-1;i++)

             for(int j=1;j<order-1;j++)

                    non_boundary_elements[counter++]=Mat[i][j];

       Arrays.sort(non_boundary_elements);

       counter = 0;

       for(int i=1;i<order-1;i++)

             for(int j=1;j<order-1;j++)

                    Mat[i][j]=non_boundary_elements[counter++];

       }

public void displayMatrix() {

       for(int i=0;i<order;i++) {

             for(int j=0;j<order;j++)

                    System.out.print(Mat[i][j]+" ");

             System.out.println();

             }

       }

public void inputMatrix() {

       Scanner in = new Scanner(System.in);

       for(int i=0;i<order;i++)

             for(int j=0;j<order;j++)

                    Mat[i][j]=in.nextInt();

       }

Matrix(int M){

       order = M;

       Mat = new int[M][M];

       sum_of_diagonals = 0;

       non_boundary_elements = new int[(M-2)*(M-2)];

       }

       private int order;

       private int[][] Mat;

       private int sum_of_diagonals;

       private int[] non_boundary_elements;

      

}