Question

Using Java:

1. Implement print2D(A) so that it prints out its 2D array argument A in the matrix form.

2. Implement add2Ds(A,B) so that it creates and returns a new 2D array C such that C=A+B.

3. Implement multiScalar2D(c,A) so that it creates and returns a new 2D array B such that

   B=c×A.

4. Implement transpose2D(A), which creates and returns a new 2D array B such that B is

   the transpose of A.

Your output should look like the following:A=

1234 5678 9 10 11 12

B=

2468 10 12 14 16 18 20 22 24

A+B=

3 6 9 12 15 18 21 24 27 30 33 36

5XA=

51015 20 25 30 35 40 45 50 55 60

Transpose of A =

159 2 6 10 3 7 11 4 8 12

Note that your methods should work for 2D arrays of any sizes.

Answer 1

If you have any doubts, please give me comment...

public class Matrix{

    public static void main(String[] args) {

        int[][] A = {{1,2,3,4}, {5,6,7,8}, {9, 10, 11, 12}};

        int[][] B = {{2,4,6,8}, {10,12,14,16}, {18,20,22,24}};

        System.out.println("A=");

        print2D(A);

        System.out.println("\nB=");

        print2D(B);

        int[][] C = add2D(A, B);

        System.out.println("\nA+B=");

        print2D(C);

        B = multiScalar(5, A);

        System.out.println("\n5XA=");

        print2D(B);        

        B = transpose2D(A);

        System.out.println("\nTranspose of A=");

        print2D(B);

    }

    public static void print2D(int[][] A){

        for(int i=0; i<A.length; i++){

            for(int j=0; j<A[i].length; j++){

                System.out.printf("%3d", A[i][j]);

            }

            System.out.println();

        }

    }

    public static int[][] add2D(int[][] A, int[][] B){

        int rows = A.length;

        int cols = A[0].length;

        int result[][] = new int[rows][cols];

        for(int i=0; i<rows; i++){

            for(int j=0; j<cols; j++){

                result[i][j] = A[i][j] + B[i][j];

            }

        }

        return result;

    }

    public static int[][] multiScalar(int c, int[][] A){

        int rows = A.length;

        int cols = A[0].length;

        int result[][] = new int[rows][cols];

        for(int i=0; i<rows; i++){

            for(int j=0; j<cols; j++){

                result[i][j] = c*A[i][j];

            }

        }

        return result;

    }

    public static int[][] transpose2D(int[][] A){

        int rows = A.length;

        int cols = A[0].length;

        int result[][] = new int[cols][rows];

        for(int i=0; i<rows; i++){

            for(int j=0; j<cols; j++){

                result[j][i] = A[i][j];

            }

        }

        return result;

    }

}