MatrixMultiplication.java

import java.util.Scanner;

public class MatrixMultiplication {

    public static void main(String[] args) {

        Scanner ez = new Scanner(System.in);
        int w, q;
        System.out.println("Enter no of row of a matrix: ");
        w = ez.nextInt();
        System.out.println("Enter no of col of a matrix: ");
        q = ez.nextInt();
        Matrix a = new Matrix(w, q);
        System.out.println("Enter no of row of b matrix: ");
        w = ez.nextInt();
        System.out.println("Enter no of col of b matrix: ");
        q = ez.nextInt();
        Matrix b = new Matrix(w, q);
        System.out.println("Enter for a matrix: ");
        a.getValues();
        System.out.println("Enter for b matrix: ");
        b.getValues();
        Matrix c = a.multiply(b);
        System.out.println("Matrix A multiplied by B:");
        c.display();
    }

}


class Matrix {

    int x, y;
    int[][] no;
    Scanner ez = new Scanner(System.in);

    public Matrix() {
        this.x = 0;
        this.y = 0;
        no = new int[this.x][this.y];
    }

    public Matrix(int x, int y) {
        this.x = x;
        this.y = y;
        no = new int[this.x][this.y];
    }

    public void getValues() {
        for (int i = 0; i < this.x; i++) {
            for (int j = 0; j < this.y; j++) {
                System.out.println("Enter [" + i + "," + j + "] no:");
                no[i][j] = ez.nextInt();
            }
        }
    }

    public static void setIn(Matrix z, int a, int b, int c) {
        z.no[a][b] = c;
    }

    public Matrix multiply(Matrix an) {
        Matrix co = new Matrix(this.x, an.y);
        if (this.y != an.x) {
            System.out.println("Can't multiply");
        } else {
            for (int a = 0; a < this.x; a++) {
                for (int b = 0; b < an.y; b++) {
                    int sum = 0;
                    for (int c = 0; c < an.x; c++) {
                        sum += this.no[a][c] * an.no[c][b];
                    }
                    Matrix.setIn(co, a, b, sum);
                }
            }
        }
        return co;
    }

    public void display() {
        for (int i = 0; i < this.x; i++) {
            for (int j = 0; j < this.y; j++) {
                System.out.print(this.no[i][j] + " ");
            }
            System.out.println();
        }
    }
}