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();
}
}
} |
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)