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 classes import 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(); } } } |
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)