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# C++ Program To Interchange Elements of First and Last Columns in Matrix

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 ``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];``        ``m[i] = 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;``    ``}``}`

Output:

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