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
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