#include <stdio.h>
#define ROW 20
#define COL 20

struct matrix
{
	double coef[ROW][COL];
	int nr;
	int nc;
};

typedef struct matrix MTRX;

int swap(MTRX *A, int swap1, int swap2);

void main ()
{
	MTRX A = {{{1., 2., 3.},{4., 5., 6.},{7., 8., 9.}},3,3};
	int i, j, swappedrows;

	printf("Enter the rows that you would like to swap.\n");
	scanf("%i %i", &i, &j);

	swappedrows = swap(&A, i, j);

	if (swappedrows)
	{
		for (i = 0; i < A.nr; i++)
		{
			printf("\n");
			for (j = 0; j < A.nc; j++)
			{
				printf("%2.0f", A.coef[i][j]);
			}
		}
	}


	return;
}

int swap(MTRX *A, int swap1, int swap2)
{
	int i;
	double temp;

	if (swap1 >= A->nr || swap2 >= A->nr)
	{
		printf("The rows cannot be swapped. One or more of the rows seleted does not exist.\n");
		return 0;
	}

	for (i = 0; i < A->nc; i++)
	{
		temp = A->coef[swap1][i];
		A->coef[swap1][i] = A->coef[swap2][i];
		A->coef[swap2][i] = temp;
		}
	return 1;
}