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Interchange elements of first and last columns in matrix

  • Difficulty Level : Easy
  • Last Updated : 19 Apr, 2021

Given a 4 x 4 matrix, the task is to interchange the elements of first and last columns and show the resulting matrix.
Examples: 
 

Input:
8 9 7 6
4 7 6 5
3 2 1 8
9 9 7 7
Output:
6 9 7 8
5 7 6 4
8 2 1 3
7 9 7 9

Input: 
9 7 5 1
2 3 4 1
5 6 6 5
1 2 3 1
Output: 
1 7 5 9
1 3 4 2
5 6 6 5
1 2 3 1

 

The approach is very simple, we can simply swap the elements of first and last column of the matrix in order to get the desired matrix as output.
Below is the implementation of the above approach : 
 

C++




// C++ code to swap the element of first
// and last column and display the result
#include <iostream>
using namespace std;
 
#define n 4
 
void interchangeFirstLast(int m[][n])
{
    // swapping of element between first
    // and last columns
    for (int i = 0; i < n; i++) {
        int t = m[i][0];
        m[i][0] = m[i][n - 1];
        m[i][n - 1] = t;
    }
}
 
// Driver function
int main()
{
    // input in the array
    int m[n][n] = { { 8, 9, 7, 6 },
                    { 4, 7, 6, 5 },
                    { 3, 2, 1, 8 },
                    { 9, 9, 7, 7 } };
 
    interchangeFirstLast(m);
 
    // printing the interchanged matrix
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++)
            cout << m[i][j] << " ";
        cout << endl;
    }
}

Java




// Java code to swap the element of first
// and last column and display the result
 
import java.io.*;
 
class GFG {
    
static int n = 4;
 
static void interchangeFirstLast(int m[][])
{
    int cols = n;
 
    // swapping of element between first
    // and last columns
    for (int i = 0; i < n; i++) {
        int t = m[i][0];
        m[i][0] = m[i][n - 1];
        m[i][n - 1] = t;
    }
}
 
// Driver function
 
    public static void main (String[] args) {
            // input in the array
    int m[][] = { { 8, 9, 7, 6 },
                    { 4, 7, 6, 5 },
                    { 3, 2, 1, 8 },
                    { 9, 9, 7, 7 } };
 
    interchangeFirstLast(m);
 
    // printing the interchanged matrix
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++)
            System.out.print(m[i][j] + " ");
            System.out.println();
    }
    }
}
// This code is contributed by inder_verma

Python 3




# Python3 code to swap the element of
# first and last column and display
# the result
   
def interchangeFirstLast(mat, n, m):
    rows = n
       
    # swapping of element between
    # first and last columns
    for i in range(n):
            t = mat[i][0];
            mat[i][0] = mat[i][n-1];
            mat[i][n-1] = t;
   
# Driver Program
mat = [[8, 9, 7, 6],
       [4, 7, 6, 5],
       [3, 2, 1, 8],
       [9, 9, 7, 7]]
   
n = 4
m = 4
interchangeFirstLast(mat, n, m)
   
# printing the interchanged matrix
for i in range(n):
    for j in range(m):
        print(mat[i][j], end = " ")
    print("\n")

C#




// C# code to swap the element of first
// and last column and display the result
using System;
 
class GFG
{
     
static int n = 4;
 
static void interchangeFirstLast(int[, ] m)
{
    int cols = n;
 
    // swapping of element between first
    // and last columns
    for (int i = 0; i < n; i++)
    {
        int t = m[i, 0];
        m[i, 0] = m[i, n - 1];
        m[i, n - 1] = t;
    }
}
 
// Driver Code
public static void Main ()
{
// input in the array
int[,] m = { { 8, 9, 7, 6 },
                { 4, 7, 6, 5 },
                { 3, 2, 1, 8 },
                { 9, 9, 7, 7 } };
 
interchangeFirstLast(m);
 
// printing the interchanged matrix
for (int i = 0; i < n; i++)
{
    for (int j = 0; j < n; j++)
        Console.Write(m[i, j] + " ");
        Console.WriteLine();
}
}
}
 
// This code is contributed
// by Akanksha Rai

PHP




<?php
// PHP code to swap the element of first
// and last column and display the result
 
function interchangeFirstLast($m, $n)
{
    $cols = $n;
 
    // swapping of element between first
    // and last columns
    for ($i = 0; $i < $n; $i++)
    {
        $t = $m[$i][0];
        $m[$i][0] = $m[$i][$n - 1];
        $m[$i][$n - 1] = $t;
    }
    return $m ;
}
     
// Driver Code
 
// input in the array
$m = array( array( 8, 9, 7, 6 ),
            array (4, 7, 6, 5 ),
            array (3, 2, 1, 8 ),
            array (9, 9, 7, 7 ));
 
$n = 4 ;
$m = interchangeFirstLast($m,$n);
 
// printing the interchanged matrix
for ($i = 0; $i < $n; $i++)
{
    for ($j = 0; $j < $n; $j++)
        echo $m[$i][$j], " ";
         
    echo "\n" ;
}
 
// This code is contributed by Ryuga
?>

Javascript




<script>
 
// Javascript code to swap the element of first
// and last column and display the result
n = 4
 
function interchangeFirstLast(m)
{
    // swapping of element between first
    // and last columns
    for (var i = 0; i < n; i++)
    {
        var t = m[i][0];
        m[i][0] = m[i][n - 1];
        m[i][n - 1] = t;
    }
}
 
// Driver function
// input in the array
m = [ [ 8, 9, 7, 6 ],
                [ 4, 7, 6, 5 ],
                [ 3, 2, 1, 8 ],
                [ 9, 9, 7, 7 ] ];
interchangeFirstLast(m);
 
// printing the interchanged matrix
for (var i = 0; i < n; i++)
{
    for (var j = 0; j < n; j++)
        document.write( m[i][j] + " ");
    document.write("<br>");
}
 
// This code is contributed by noob2000.
</script>
Output: 
6 9 7 8 
5 7 6 4 
8 2 1 3 
7 9 7 9

 

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