Intercambiar elementos de la primera y última fila en array

Dada una array de 4 x 4, tenemos que intercambiar los elementos de la primera y la última fila y mostrar la array resultante.
Ejemplos: 
 

Input : 3 4 5 0
        2 6 1 2
        2 7 1 2
        2 1 1 2
Output : 2 1 1 2
         2 6 1 2
         2 7 1 2
         3 4 5 0

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

El enfoque es muy simple, simplemente podemos intercambiar los elementos de la primera y la última fila de la array para obtener la array deseada como salida.
A continuación se muestra la implementación del enfoque: 
 

// C++ code to swap the element of first
// and last row and display the result
#include <iostream>
using namespace std;
 
#define n 4
 
void interchangeFirstLast(int m[][n])
{
        int rows = n;
         
        // swapping of element between first
        // and last rows
        for (int i = 0; i < n; i++)
        {
            int t = m[0][i];
            m[0][i] = m[rows - 1][i];
            m[rows - 1][i] = 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;
    }
}
 
// This code is contributed by Anant Agarwal.

// Java code to swap the element of first
// and last row and display the result
import java.io.*;
 
public class Interchange {
     
    static void interchangeFirstLast(int m[][])
    {
        int rows = m.length;
         
        // swapping of element between first
        // and last rows
        for (int i = 0; i < m[0].length; i++) {
            int t = m[0][i];
            m[0][i] = m[rows-1][i];
            m[rows-1][i] = t;
        }
    }
     
    // Driver code
    public static void main(String args[]) throws IOException
    {
        // 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 < m.length; i++) {
            for (int j = 0; j < m[0].length; j++)
                System.out.print(m[i][j] + " ");
            System.out.println();
        }
    }
}

# Python code to swap the element
# of first and last row and display
# the result
 
def interchangeFirstLast(mat, n, m):
    rows = n
     
    # swapping of element between
    # first and last rows
    for i in range(n):
        t = mat[0][i]
        mat[0][i] = mat[rows-1][i]
        mat[rows-1][i] = 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")
 
# This code is contributed by Shrikant13.

// C# code to swap the element of first
// and last row and display the result
using System;
 
class GFG
{
 
public static void interchangeFirstLast(int[][] m)
{
    int rows = m.Length;
 
    // swapping of element between first
    // and last rows
    for (int i = 0; i < m[0].Length; i++)
    {
        int t = m[0][i];
        m[0][i] = m[rows - 1][i];
        m[rows - 1][i] = t;
    }
}
 
// Driver code
public static void Main(string[] args)
{
    // input in the array
    int[][] m = new int[][]
    {
        new int[] {8, 9, 7, 6},
        new int[] {4, 7, 6, 5},
        new int[] {3, 2, 1, 8},
        new int[] {9, 9, 7, 7}
    };
 
    interchangeFirstLast(m);
 
    // printing the interchanged matrix
    for (int i = 0; i < m.Length; i++)
    {
        for (int j = 0; j < m[0].Length; j++)
        {
            Console.Write(m[i][j] + " ");
        }
        Console.WriteLine();
    }
}
}
 
// This code is contributed by Shrikant13

<?php
// PHP code to swap the element of first
// and last row and display the result
$n = 4;
 
function interchangeFirstLast(&$m)
{
        global $n;
        $rows = $n;
          
        // swapping of element between first
        // and last rows
        for ($i = 0; $i < $n; $i++)
        {
            $t = $m[0][$i];
            $m[0][$i] = $m[$rows - 1][$i];
            $m[$rows - 1][$i] = $t;
        }
}
  
// Driver function
 
// 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));
              
interchangeFirstLast($m);
  
// printing the interchanged matrix
for ($i = 0; $i < $n; $i++)
{
    for ($j = 0; $j < $n; $j++)
        echo $m[$i][$j] . " ";
    echo "\n";
}
?>

<script>
// Javascript code to swap the element of first
// and last row and display the result
     
    function interchangeFirstLast(m)
    {
        let rows = m.length;
           
        // swapping of element between first
        // and last rows
        for (let i = 0; i < m[0].length; i++) {
            let t = m[0][i];
            m[0][i] = m[rows-1][i];
            m[rows-1][i] = t;
        }
    }
     
    // Driver code
     
    // input in the array
    let m = [[8, 9, 7, 6],
          [4, 7, 6, 5],
       [3, 2, 1, 8],
       [9, 9, 7, 7]]
        interchangeFirstLast(m);
           
     // printing the interchanged matrix
     for (let i = 0; i < m.length; i++) {
        for (let j = 0; j < m[0].length; j++)
            document.write(m[i][j] + " ");
        document.write("<br>");
     }
     
     
    // This code is contributed by avanitrachhadiya2155
</script>

Producción : 
 

9 9 7 7 
4 7 6 5 
3 2 1 8 
8 9 7 6 

Complejidad temporal: O(n)
Espacio auxiliar: O(1)