Skip to content
Related Articles

Related Articles

Java Program to Accept a Matrix of Order M x N & Interchange the Diagonals
  • Difficulty Level : Expert
  • Last Updated : 04 Nov, 2020

Problem Description: Write a Java program that accepts a matrix of M × N order and then interchange diagonals of the matrix.

Steps:  

1. We can only interchange diagonals for a square matrix.

2. Create a square matrix of size [M × M].

3. Check the matrix is a square matrix or not. If the matrix is square then follow step 3 else terminate the program.



4. Apply logic for interchange diagonal of the matrix some logic is given below.

Method 1: Swap element a[i][i] and a[i][n – i -1]

               for (j = 0; j < m; j++) {

               temp = a[j][j];

               a[j][j] = a[j][n – 1 – j];

               a[j][n – 1 – j] = temp;

           }

Example:



Java




//  Java Program to Accept a Matrix of Order M x N &
//  Interchange the Diagonals
  
import java.util.Scanner;
public class InterchangeDiagonals {
    public static void main(String[] args)
    {
        // declare variable
        int m, n, i, j, temp;
  
        // create a object of scanner class
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter number of rows ");
  
        // take number of rows
        m = sc.nextInt();
  
        System.out.print("Enter number of columns ");
  
        // take number of columns
        n = sc.nextInt();
  
        // declare a mxn order array
        int a[][] = new int[m][n];
  
        // if block it's execute when m is equals to n
        if (m == n) {
            System.out.println(
                "Enter all the values of matrix ");
  
            // take the matrix inputs
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    a[i][j] = sc.nextInt();
                }
            }
  
            System.out.println("original Matrix:");
  
            // print the original matrix
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    System.out.print(a[i][j] + " ");
                }
                System.out.println("");
            }
  
            // perfom interchange
            for (j = 0; j < m; j++) {
                temp = a[j][j];
                a[j][j] = a[j][n - 1 - j];
                a[j][n - 1 - j] = temp;
            }
            System.out.println(
                " after interchanging diagonals of matrix ");
  
            // print interchanged matrix
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    System.out.print(a[i][j] + " ");
                }
                System.out.println("");
            }
        }
  
        // else block it's only execute when m is not equals
        // to n
        else {
            System.out.println("Rows not equal to columns");
        }
    }
}

Output:

Enter number of rows 3

Enter number of columns 3

Enter all the values of matrix  

1

2

3

4

5

6

7

8

9

Original Matrix:

1   2   3  

4   5   6  

7   8   9  

After interchanging diagonals of matrix  

3   2   1  

4   5   6  

9   8   7 

Example 2:

Java




//  Java Program to Accept a Matrix of Order MxN &
//  Interchange the Diagonals
  
import java.util.Scanner;
public class InterchangeDiagonals {
    public static void main(String[] args)
    {
        // declare variable
        int m, n, i, j, temp;
  
        // create a object of scanner class
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter number of rows ");
  
        // take number of rows
        m = sc.nextInt();
  
        System.out.print("Enter number of columns ");
  
        // take number of columns
        n = sc.nextInt();
  
        // declare a mxn order array
        int a[][] = new int[m][n];
  
        // if block it's execute when m is equals to n
        if (m == n) {
            System.out.println(
                "Enter all the values of matrix ");
  
            // take input matrix
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    a[i][j] = sc.nextInt();
                }
            }
  
            System.out.println("original Matrix:");
  
            // print original matrix
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    System.out.print(a[i][j] + " ");
                }
                System.out.println("");
            }
  
            // perfoming interchange
            for (j = 0; j < m; j++) {
                temp = a[j][j];
                a[j][j] = a[j][n - 1 - j];
                a[j][n - 1 - j] = temp;
            }
            System.out.println(
                " after interchanging diagonals of matrix ");
  
            // print interchanged matrix
            for (i = 0; i < m; i++) {
                for (j = 0; j < n; j++) {
                    System.out.print(a[i][j] + " ");
                }
                System.out.println("");
            }
        }
  
        // else block it's only execute when m is not equals
        // to n
        else {
            System.out.println("Rows not equal to columns");
        }
    }
}

Output:

Enter number of rows 2

Enter number of columns 1

Enter all the values of matrix  

1

2

Rows not equal to columns

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

My Personal Notes arrow_drop_up
Recommended Articles
Page :