# Interchange elements of first and last rows in matrix

Given a 4 x 4 matrix, we have to interchange the elements of first and last row and show the resulting matrix.

Examples :

```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
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

The approach is very simple, we can simply swap the elements of first and last row of the matrix inorder to get the desired matrix as output.

Below is the implementation of the approach :

## C++

 `// C++ code to swap the element of first ` `// and last row and display the result ` `#include ` `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[i]; ` `            ``m[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

 `// 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(); ` `        ``} ` `    ``} ` `} `

## Python3

 `# 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#

 `// 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.Length; i++) ` `    ``{ ` `        ``int` `t = m[i]; ` `        ``m[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.Length; j++) ` `        ``{ ` `            ``Console.Write(m[i][j] + ``" "``); ` `        ``} ` `        ``Console.WriteLine(); ` `    ``} ` `} ` `} ` ` `  `// This code is contributed by Shrikant13 `

## PHP

 ` `

Output :

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

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