/* Calculs matriciels */

#include 

/* Saisie d'une matrice carree */
void saisir(double Mat[100][100], int nb);

/* Affichage d'une matrice carree */
void afficher(double Mat[100][100], int nb);

/* Addition de deux matrices */
void additionner(double Mat1[100][100], double Mat2[100][100],
		 double Mat3[100][100], int nb);

/* Multiplication de deux matrices */
void multiplier(double Mat1[100][100], double Mat2[100][100],
		double Mat3[100][100], int nb);

/* Affichage d'un menu et retour du choix de l'utilisateur */
char menu();

int main ()
{
	double M[100][100], P[100][100], R[100][100];
	int nb_val;
	char rep;

	rep = menu();
	while (rep == 'A' || rep == 'M')
	{
		printf ("taille de la matrice carree :\n");
		scanf ("%d", &nb_val);

		printf("saisie de la 1ere matrice\n");
		saisir(M, nb_val);

		printf("saisie de la 2eme matrice\n");
		saisir(P, nb_val);

		switch(rep)
		{
		case 'A':
			additionner(M, P, R, nb_val);
			break;
		case 'M':
			multiplier(M, P, R, nb_val);
			break;
		}

		printf("Matrice M:\n"); afficher(M, nb_val);
		printf("Matrice P:\n"); afficher(P, nb_val);
		printf("Matrice R:\n"); afficher(R, nb_val);

		rep = menu();
	}

	return 0;
}

char menu(void)
{
	char rep;
	printf("A...........Addition\n");
	printf("M...........Multiplication\n");
	printf("(autres)....Quitter\n");
	printf("Choix : ");
	scanf(" %c", &rep);
	if (rep > 'Z')
	{
		rep = rep - 'a' + 'A';
	}
	return rep;
}

void saisir(double Mat[100][100], int nb)
{
	int i, j;
	printf("entrer les valeurs de la matrice\n");
	for (i=0; i<nb; i++)
	{
		 for (j=0; j<nb; j++)
		 {
			printf ("M[%d][%d] = ", i+1, j+1);
			scanf ("%lf", &(Mat[i][j]));
		 }
	}
}

void afficher(double Mat[100][100], int nb)
{
	int i, j;

	printf("\t");
	for (i=0; i<nb; i++)
	{
		printf("%d\t\t", i+1);
	}
	printf("\n");

	for (i=0; i<nb; i++)
	{
		printf("----------------");
	}
	printf("\n");

	for (i=0; i<nb; i++)
	{
		printf("%d:", i+1);
		for (j=0; j<nb; j++)
		{
			printf ("\t%f", Mat[i][j]);
		}
		printf("\n");
	}

	for (i=0; i<nb; i++)
	{
		printf("----------------");
	}
	printf("\n\n");
}

void additionner(double Mat1[100][100], double Mat2[100][100],
		 double Mat3[100][100], int nb)
{
	int i, j;
	for (i=0; i<nb; i++)
	{
		for (j=0; j<nb; j++)
		{
			Mat3[i][j] = Mat1[i][j] + Mat2[i][j];
		}
	}
}

void multiplier(double Mat1[100][100], double Mat2[100][100],
		double Mat3[100][100], int nb)
{
	 int i, j, k;
	 for (i=0; i<nb; i++)
	 {
		for (j=0; j<nb; j++)
		{
			Mat3[i][j] = 0;
			for (k=0; k<nb; k++)
			{
				Mat3[i][j] = Mat3[i][j] + Mat1[i][k]*Mat2[k][j];
			}
		}
	}
}