MIT-Curricular/OOP/Java/Lab/Week4/MatrixMulp.java

import java.util.Scanner;

class MatrixMulp {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println(
            "Enter the number of rows and columns in the matrix A: "
        );
        int m = sc.nextInt();
        int n = sc.nextInt();
        System.out.println(
            "Enter the number of rows and columns in the matrix B: "
        );
        int p = sc.nextInt();
        int q = sc.nextInt();

        System.out.println(
            "Matrices are " +
            ((m == p && n == q) ? "" : "not ") +
            "compatible for addition."
        );
        System.out.println(
            "Matrices are " +
            ((n == p) ? "" : "not ") +
            "compatible for multiplication."
        );

        int[][] A = new int[m][n];
        int[][] B = new int[p][q];

        System.out.println("Enter the elements of matrix A:");
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                A[i][j] = sc.nextInt();
            }
        }

        System.out.println("Enter the elements of matrix B:");
        for (int i = 0; i < p; i++) {
            for (int j = 0; j < q; j++) {
                B[i][j] = sc.nextInt();
            }
        }

        // Adding matrices
        System.out.println("Result of addition:");
        if (m == p && n == q) {
            int C[][] = new int[m][n];
            for (int i = 0; i < m; i++) {
                for (int j = 0; j < n; j++) {
                    C[i][j] = A[i][j] + B[i][j];
                    System.out.print(C[i][j] + " ");
                }
                System.out.println();
            }
        }

        // Multiplying matrices
        System.out.println("Result of multiplication:");
        if (n == p) {
            int D[][] = new int[m][q];
            for (int i = 0; i < m; i++) {
                for (int j = 0; j < q; j++) {
                    for (int k = 0; k < n; k++) {
                        D[i][j] += A[i][k] * B[k][j];
                    }
                    System.out.print(D[i][j] + " ");
                }
                System.out.println();
            }
        }
    }
}