Java Program to Find Product of Sum of First Column and Last Column

In this article we are going to see how we can write a program to find product of sum of first column and last column using JAVA language.

Java Program to Find Product of Sum of First Column and Last Column

A 3*3 Matrix is having 3 rows and 3 columns where this 3*3 represents the dimension of the matrix. Means there are 3*3 i.e. total 9 elements in a 3*3 Matrix.

Let’s understand it in more simpler way.

                   | A00   A01   A02 |
Matrix A =  | A10   A11   A12 |
                   | A20   A21   A22 | 3*3
  • Matrix A represents a 3*3 matrix.
  • A‘ represents the matrix element
  • Aij‘ represents the matrix element at it’s matrix position/index.
  • i‘ represents the row index
  • j‘ represents the column index
  • Means A00=Aij  where i=0 and j=0A01=aij where i=0 and j=1 and like this.
  • Here we have started row value from 0 and column value from 0.

Let’s see different ways to find product of sum of first column and last column.

Method-1: Java Program to Find Product of Sum of First Column and Last Column By Static Initialization of Array Elements

Approach:

  • Initialize and declare one array with size 3×3 which is for matrix.
  • Use two for loops to iterate the rows and columns .
  • Inside the for loops calculate the sum of first column elements and last column elements.
  • Then find the product between sum of first column elements and last column elements.
  • Print the result using a for loop.

Program:

public class Matrix
{
    public static void main(String args[])
    {

        // Initializing the 3X3 matrix i.e. 2D array
        int arr[][] = {{10,20,30},{40,40,60},{70,80,90}};
        int row, col ;
        //firstColumnSum and lastColumnSum initialized as 0
        int firstColumnSum=0;
        int lastColumnSum=0;
        

        System.out.print("The matrix elements are : ");
        printMatrix(arr);

        // Loops to calculate the sum of first column elements and last column elements
        for(row=0;row<3;row++)
        {
            for(col=0;col<3;col++)
            {
                //finding the sum of all elements of first row
                if(col==0)
                    firstColumnSum = firstColumnSum+arr[row][0];
                //finding the sum of all elements of last row
                else if(col==2)
                    lastColumnSum = lastColumnSum+arr[row][2];
            }   
        }
        
        
        System.out.println("Sum of all the elements of first column: "+firstColumnSum);
        System.out.println("Sum of all the elements of last column: "+lastColumnSum);
        
        //finding product between sum of first column elements and last column elements
        int product=firstColumnSum*lastColumnSum;
       
       //Printing the difference between sum of all rows and all columns
        System.out.print("\nProduct between Sum of first column and last column elements : "+product);

    }
    
    //Method to print the matrix
    static void printMatrix(int arr[][])
    {
        int row, col;
        // Loop to print the elements
        for(row=0;row<3;row++)
        {
            // Used for formatting
            System.out.print("\n");
            for(col=0;col<3;col++)
            {
                System.out.print(arr[row][col]+" ");
            }
        }
        System.out.print("\n");
    }
}
Output:

The matrix elements are : 
10 20 30 
40 40 60 
70 80 90 
Sum of all the elements of first column: 120
Sum of all the elements of last column: 180

Product between Sum of first column and last column elements : 21600

Method-2: Java Program to Find Product of Sum of First Column and Last Column By Dynamic Initialization of Array Elements

Approach:

  • Declare one array with size 3×3 which is for matrix.
  • Ask the user for input of matrix elements.
  • Use two for loops to iterate the rows and columns .
  • Inside the for loops calculate the sum of first column elements and last column elements.
  • Then find the product between sum of first column elements and last column elements.
  • Print the result using a for loop.

Program:

import java.util.*;

public class Matrix
{
    public static void main(String args[])
    {

        //Scanner class to take input
        Scanner scan = new Scanner(System.in);
        // Initializing the 3X3 matrix i.e. 2D array
        int arr[][] = new int[3][3];
        int row, col ;
        
        //firstColumnSum and lastColumnSum initialized as 0
        int firstColumnSum=0; 
        int lastColumnSum=0;
        
        // Taking matrix input
        System.out.println("Enter matrix elements : ");
        for(row=0;row<3;row++)
            for(col=0;col<3;col++)
                arr[row][col] = scan.nextInt();
        

        System.out.print("The matrix elements are : ");
        printMatrix(arr);

        // Loops to calculate the sum of first column elements and last column elements
        for(row=0;row<3;row++)
        {
            for(col=0;col<3;col++)
            {
                //finding the sum of all elements of first row
                if(col==0)
                    firstColumnSum = firstColumnSum+arr[row][0];
                //finding the sum of all elements of last row
                else if(col==2)
                    lastColumnSum = lastColumnSum+arr[row][2];
            }   
        }
        
        
        System.out.println("Sum of all the elements of first column: "+firstColumnSum);
        System.out.println("Sum of all the elements of last column: "+lastColumnSum);
        
        //finding product between sum of first column elements and last column elements
        int product=firstColumnSum*lastColumnSum;
       
       //Printing the difference between sum of all rows and all columns
        System.out.print("\nProduct between Sum of first column and last column elements : "+product);

    }
    
    //Method to print the matrix
    static void printMatrix(int arr[][])
    {
        int row, col;
        // Loop to print the elements
        for(row=0;row<3;row++)
        {
            // Used for formatting
            System.out.print("\n");
            for(col=0;col<3;col++)
            {
                System.out.print(arr[row][col]+" ");
            }
        }
        System.out.print("\n");
    }
}
Output:

Enter matrix elements : 
The matrix elements are : 
9 5 1 
7 4 8 
2 6 3 
Sum of all the elements of first column: 18
Sum of all the elements of last column: 12

Product between Sum of first column and last column elements : 216

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