Java Program to Interchange Elements of First and Last in a Matrix Across Columns
For a given 4 x 4 matrix, the task is to interchange the elements of the first and last columns and then return the resultant matrix.
Examples :
Input 1 : 1 1 5 0
2 3 7 2
8 9 1 3
6 7 8 2
Output 1 : 0 1 5 1
2 3 7 2
3 9 1 8
2 7 8 6
Input 2 : 7 8 9 10
11 13 14 1
15 7 12 22
11 21 30 1
Output 2 : 10 8 9 7
1 13 14 11
22 7 12 15
1 21 30 11
Approach:
To get the required output, we need to swap the elements of the first and last column of the stated matrix.
Example
Java
// Java Program to Interchange Elements of the// First and Last Column in a Matrix// Importing input output classesimport java.io.*;class GFG { // Declare static variable and initialize to // order of the matrix static int N = 3; // Method 1 // To swap first and last column in a matrix static void Swap_First_Last(int mat[][]) { int cls = N; // Interchanging of elements between the // first and last columns for (int j = 0; j < N; j++) { int temp = mat[j][0]; mat[j][0] = mat[j][N - 1]; mat[j][N - 1] = temp; } } // Method 2 // Main driver method public static void main(String[] args) { // Creating 2D integer element matrix // Custom input matrix int mat[][] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } }; // Outer loop for rows for (int j = 0; j < N; j++) { // Inner loop for columns for (int k = 0; k < N; k++) { // Print the input matrix System.out.print(mat[j][k] + " "); } // Operations over a row is computed so new line System.out.println(); } System.out.println("Swapped Matrix as follows : "); // Now, calling the (Method1) to interchange // first and last columns in above matrix Swap_First_Last(mat); // Now simply print the updated matrix // Swapped matrix using nested for loops // Outer loop for rows for (int j = 0; j < N; j++) { // Inner loop for columns for (int k = 0; k < N; k++) // Print the swapped matrix System.out.print(mat[j][k] + " "); // Operations over a row is computed so new line System.out.println(); } }} |
Output
1 2 3 4 5 6 7 8 9 Swapped Matrix as follows : 3 2 1 6 5 4 9 8 7
Time Complexity: O(N2)
Auxiliary Space: O(1)
