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 MatrixÂ
// Importing input output classesimport java.io.*;Â
class GFG {Â
    // Declare static variable and initialize to    // order of the matrix    static int N = 3;Â
    // Method 1    // To swap first and last column in a matrix    static void Swap_First_Last(int mat[][])    {        int cls = N;Â
        // 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;        }    }Â
    // 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 } };Â
        // Outer loop for rows        for (int j = 0; j < N; j++) {Â
            // Inner loop for columns            for (int k = 0; k < N; k++) {Â
                // Print the input matrix                System.out.print(mat[j][k] + " ");            }            // Operations over a row is computed so new line            System.out.println();        }Â
        System.out.println("Swapped Matrix as follows : ");Â
        // Now, calling the (Method1) to interchange        // first and last columns in above matrix        Swap_First_Last(mat);Â
        // Now simply print the updated matrix        // Swapped matrix using nested for loopsÂ
        // Outer loop for rows        for (int j = 0; j < N; j++) {Â
            // Inner loop for columns            for (int k = 0; k < N; k++)Â
                // Print the swapped matrix                System.out.print(mat[j][k] + " ");Â
            // 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)
