/*
 * C program to accept a matrix of order M x N and store its elements
 * and interchange the main diagonal elements of the matrix
 * with that of the secondary diagonal elements
 */
#include <stdio.h>

void main ()
{
    static int array[10][10];
    int i, j, m, n, a;
    printf("Enter the order of the matix \n");
    scanf("%d %d", &m, &n);
    if (m == n)
        {
            printf("Enter the co-efficients of the matrix\n");
            for (i = 0; i < m; ++i)
                {
                    for (j = 0; j < n; ++j)
                        {
                            scanf("%dx%d", &array[i][j]);
                        }
                }
            printf("The given matrix is \n");
            for (i = 0; i < m; ++i)
                {
                    for (j = 0; j < n; ++j)
                        {
                            printf(" %d", array[i][j]);
                        }
                    printf("\n");
                }
            for (i = 0; i < m; ++i)
                {
                    a = array[i][i];
                    array[i][i] = array[i][m - i - 1];
                    array[i][m - i - 1] = a;
                }
            printf("The matrix after changing the \n");
            printf("main diagonal & secondary diagonal\n");
            for (i = 0; i < m; ++i)
                {
                    for (j = 0; j < n; ++j)
                        {
                            printf(" %d", array[i][j]);
                        }
                    printf("\n");
                }
        }
    else
        printf("The given order is not square matrix\n");
}