C Program to Interchange Elements of First and Last in a Matrix Across Columns

// C program to swap the element of first and last column of
// the matrix and display the result
#include <stdio.h>
#define n 3 // macros

void interchangeFirstLast(int mat[][n])
{
    // swap the elements between first and last columns
    for (int i = 0; i < n; i++) {
        int t = mat[i][0];
        mat[i][0] = mat[i][n - 1];
        mat[i][n - 1] = t;
    }
}

// Driver code
int main()
{
    // input matrix
    int mat[n][n]
        = { { 2, 4, 6 }, { 8, 2, 3 }, { 1, 9, 4 } };

    // print input matrix
    printf("Input Matrix: \n");
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            printf("%d ", mat[i][j]);
        }
        printf("\n");
    }

    // call interchangeFirstLast(mat) function.
    // This function swap the element of first and last
    // columns.

    interchangeFirstLast(mat);

    // print output matrix
    printf("Output Matrix: \n");
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            printf("%d ", mat[i][j]);
        }
        printf("\n");
    }
}