Question

JAVA

Write a program that prompts the user to enter a matrix number of rows and number of columns.
In main method create 2D matrix based on the number of rows and columns input by the user; randomly fills the matrix with 0s and 1s and prints it.
Create method sumColumns that takes only the matrix you created in main method and find the sum of each column with even index and prints it. Do not use global variables.

Here is a sample run of the program:

Enter number of rows and columns 4 6
1 0 0 0 1 0
0 0 0 0 1 0
1 0 1 0 1 1
1 1 1 1 0 1
3 2 3
Process finished with exit code 0

Answer 1

CODE -

import java.util.Scanner;

import java.util.Random;

public class matrix {

    // FUNCTION TO FIND AND DISPLAY SUM OF EACH COLUMN OF THE MATRIX AT EVEN INDEX

    static void sumColumns(int[][] matrix)

    {

        // FINDING THE NUMBER OF ROWS IN THE MATRIX

        int row = matrix.length;

        // FINDING THE NUMBER OF COLUMNS IN THE MATRIX

        int column = matrix[0].length;

        // LOOP TO FIND AND PRINT SUM OF EACH COLUMNS AT EVEN INDEX

        for(int i=0; i<column; i = i+2)

        {

            int sum_column = 0;

            for(int j=0; j<row; j++)

                sum_column += matrix[j][i];

            System.out.print(sum_column + " ");

        }

    }

    // MAIN FUNCTION

    public static void main(String[] args)

    {

        int row, column;

        Scanner keyboard = new Scanner(System.in);

        Random rand = new Random();

        // TAKING NUMBER OF ROW AND NUMBER OF COLUMN AS INPUT FROM THE USER

        System.out.print("Enter number of rows and columns ");

        row = keyboard.nextInt();

        column = keyboard.nextInt();

        // CREATING A MATRIX OF SIZE ENTERED BY THE USER

        int[][] matrix = new int[row][column];

        // FILLING THE MATRIX RANDOMLY WITH 0 AND 1

        for(int i=0; i<row; i++)

            for(int j=0; j<column; j++)

                matrix[i][j] = rand.nextInt(2);

        // DISPLAYING THE MATRIX

        for(int i=0; i<row; i++)

        {

            for(int j=0; j<column; j++)

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

            System.out.println();

        }

        // CALLING THE sumColumns FUNCTION.

        sumColumns(matrix);

        keyboard.close();

    }

}

SCREENSHOTS -

CODE -

OUTPUT -

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