multiply two square matrices on a single processor

/* serial_mat_mult.c -- multiply two square matrices on a single processor
*
* Input:
* n: order of the matrices
* A,B: factor matrices
*
* Output:
* C: product matrix
*
* See Chap 7, pp. 111 & ff in PPMPI
*/
#include

#define MAX_ORDER 10

typedef float MATRIX_T[MAX_ORDER][MAX_ORDER];

main() {
int n;
MATRIX_T A;
MATRIX_T B;
MATRIX_T C;

void Read_matrix(char* prompt, MATRIX_T A, int n);
void Serial_matrix_mult(MATRIX_T A, MATRIX_T B, MATRIX_T C, int n);
void Print_matrix(char* title, MATRIX_T C, int n);

printf("What's the order of the matrices?\n");
scanf("%d", &n);

Read_matrix("Enter A", A, n);
Print_matrix("A = ", A, n);
Read_matrix("Enter B", B, n);
Print_matrix("B = ", B, n);
Serial_matrix_mult(A, B, C, n);
Print_matrix("Their product is", C, n);

} /* main */


/*****************************************************************/
void Read_matrix(
char* prompt /* in */,
MATRIX_T A /* out */,
int n /* in */) {
int i, j;

printf("%s\n", prompt);
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
scanf("%f", &A[i][j]);
} /* Read_matrix */


/*****************************************************************/
/* MATRIX_T is a two-dimensional array of floats */
void Serial_matrix_mult(
MATRIX_T A /* in */,
MATRIX_T B /* in */,
MATRIX_T C /* out */,
int n /* in */) {

int i, j, k;

void Print_matrix(char* title, MATRIX_T C, int n);

Print_matrix("In Serial_matrix_mult A = ", A, n);
Print_matrix("In Serial_matrix_mult B = ", B, n);

for (i = 0; i < n; i++)
for (j = 0; j < n; j++) {
C[i][j] = 0.0;
for (k = 0; k < n; k++)
C[i][j] = C[i][j] + A[i][k]*B[k][j];
printf("i = %d, j = %d, c_ij = %f\n", i, j, C[i][j]);
}
} /* Serial_matrix_mult */


/*****************************************************************/
void Print_matrix(
char* title /* in */,
MATRIX_T C /* out */,
int n /* in */) {
int i, j;

printf("%s\n", title);
for (i = 0; i < n; i++) {
for (j = 0; j < n; j++)
printf("%4.1f ", C[i][j]);
printf("\n");
}
} /* Read_matrix */