when I execute the "A" program the result is displayed , but when i trying to add a piece "B" of code aims to read a .txt file  nothing appear:

program A:

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#include <malloc.h>

#include <stdlib.h>

#include <stdio.h>

#include <time.h>

#include "math.h"

#include "mpi.h"

#define MAX_LIGNE 20   /* au maximum, 10 lignes */

#define MAX_COL    20   /* au maximum 8 colonnes */

#define NOM_A_LIRE "fichier1.txt" /*matrice a lire*/

typedef int Matrice[MAX_LIGNE][MAX_COL];

int main(int argc, char** argv)

{

int          taskid, ntasks;

int          ierr, i, itask;

int         sendcounts[2048], displs[2048], recvcount;

double       **sendbuff, *recvbuff, buffsum, buffsums[2048];

double       inittime, totaltime;

const int nbr_etat = 10;

double tab[nbr_etat];

for (int i = 0; i < nbr_etat; i++)

tab[i] = i;

for (int i = 0; i < nbr_etat; i++)

printf("%0.0f ", tab[i]);

printf("\n");

int nbr_elm[2] = { 4, 6 };

int dpl[2] = { 0, 4 };

MPI_Init(&argc, &argv);

MPI_Comm_rank(MPI_COMM_WORLD, &taskid);

MPI_Comm_size(MPI_COMM_WORLD, &ntasks);

recvbuff = (double *)malloc(sizeof(double)*nbr_etat);

if (taskid == 0)

{

sendbuff = (double **)malloc(sizeof(double *)*ntasks);// on execute pour deux proc

sendbuff[0] = (double *)malloc(sizeof(double)*ntasks*nbr_etat);

for (i = 1; i < ntasks; i++)

{

sendbuff[i] = sendbuff[i - 1] + nbr_etat;

}

}

else

{

sendbuff = (double **)malloc(sizeof(double *)* 1);

sendbuff[0] = (double *)malloc(sizeof(double)* 1);

}

if (taskid == 0){

srand((unsigned)time(NULL) + taskid);

for (itask = 0; itask<ntasks; itask++)

{

int k;

displs[itask] = itask*nbr_etat;

int s = dpl[itask];

sendcounts[itask] = nbr_elm[itask];

for (i = 0; i<sendcounts[itask]; i++)

{

k = i + s;

sendbuff[itask][i] = tab[k];

printf("+ %0.0f  ", sendbuff[itask][i]);

}

printf("\n");

}

}

recvcount = nbr_elm[taskid];

inittime = MPI_Wtime();

ierr = MPI_Scatterv(sendbuff[0], sendcounts, displs, MPI_DOUBLE,

recvbuff, recvcount, MPI_DOUBLE,

0, MPI_COMM_WORLD);

totaltime = MPI_Wtime() - inittime;

printf("\n >>>> \n");

buffsum = 0.0;

printf("\n > %d < \n", taskid);

for (i = 0; i<recvcount; i++)

{

buffsum = buffsum + recvbuff[i];

printf("* %0.0f ", recvbuff[i]);

}

printf("\n");

printf("(%d) %0.3f ", taskid, buffsum);

ierr = MPI_Gather(&buffsum, 1, MPI_DOUBLE,

buffsums, 1, MPI_DOUBLE,

0, MPI_COMM_WORLD);

if (taskid == 0)

{

printf("\n");

printf("##########################################################\n\n");

printf("                --> APReS COMMUNICATION <-- \n\n");

for (itask = 0; itask<ntasks; itask++)

{

printf("Processus %d : Somme du vecteur reçu : %0.0f\n",

itask, buffsums[itask]);

}

printf("\n");

printf("##########################################################\n\n");

printf(" Temps total de communication : %f secondes\n\n", totaltime);

printf("##########################################################\n\n");

}

/* Libération de la mémoire                                      */

if (taskid == 0)

{

free(sendbuff[0]);

free(sendbuff);

}

else

{

free(sendbuff[0]);

free(sendbuff);

free(recvbuff);

}

/* Finalisation de MPI                                           */

MPI_Finalize();

}

program B:

------------------------- 

#include <malloc.h>

#include <stdlib.h>

#include <stdio.h>

#include <time.h>

#include "math.h"

#include "mpi.h"

#define MAX_LIGNE 20   /* au maximum, 10 lignes */

#define MAX_COL    20   /* au maximum 8 colonnes */

#define NOM_A_LIRE "fichier1.txt" /*matrice a lire*/

typedef int Matrice[MAX_LIGNE][MAX_COL];

int main(int argc, char** argv)

{

int          taskid, ntasks;

int          ierr, i, itask;

int         sendcounts[2048], displs[2048], recvcount;

double       **sendbuff, *recvbuff, buffsum, buffsums[2048];

double       inittime, totaltime;

const int nbr_etat = 10;

double tab[nbr_etat];

for (int i = 0; i < nbr_etat; i++)

tab[i] = i;

for (int i = 0; i < nbr_etat; i++)

printf("%0.0f ", tab[i]);

printf("\n");

int nbr_elm[2] = { 4, 6 };

int dpl[2] = { 0, 4 };

MPI_Init(&argc, &argv);

MPI_Comm_rank(MPI_COMM_WORLD, &taskid);

MPI_Comm_size(MPI_COMM_WORLD, &ntasks);

recvbuff = (double *)malloc(sizeof(double)*nbr_etat);

if (taskid == 0)

{

sendbuff = (double **)malloc(sizeof(double *)*ntasks);// on execute pour deux proc

sendbuff[0] = (double *)malloc(sizeof(double)*ntasks*nbr_etat);

for (i = 1; i < ntasks; i++)

{

sendbuff[i] = sendbuff[i - 1] + nbr_etat;

}

}

else

{

sendbuff = (double **)malloc(sizeof(double *)* 1);

sendbuff[0] = (double *)malloc(sizeof(double)* 1);

}

if (taskid == 0){

srand((unsigned)time(NULL) + taskid);

for (itask = 0; itask<ntasks; itask++)

{

int k;

displs[itask] = itask*nbr_etat;

int s = dpl[itask];

sendcounts[itask] = nbr_elm[itask];

for (i = 0; i<sendcounts[itask]; i++)

{

k = i + s;

sendbuff[itask][i] = tab[k];

printf("+ %0.0f  ", sendbuff[itask][i]);

}

printf("\n");

}

}

recvcount = nbr_elm[taskid];

inittime = MPI_Wtime();

ierr = MPI_Scatterv(sendbuff[0], sendcounts, displs, MPI_DOUBLE,

recvbuff, recvcount, MPI_DOUBLE,

0, MPI_COMM_WORLD);

totaltime = MPI_Wtime() - inittime;

printf("\n >>>> \n");

buffsum = 0.0;

printf("\n > %d < \n", taskid);

for (i = 0; i<recvcount; i++)

{

buffsum = buffsum + recvbuff[i];

printf("* %0.0f ", recvbuff[i]);

}

printf("\n");

printf("(%d) %0.3f ", taskid, buffsum);

ierr = MPI_Gather(&buffsum, 1, MPI_DOUBLE,

buffsums, 1, MPI_DOUBLE,

0, MPI_COMM_WORLD);

if (taskid == 0)

{

printf("\n");

printf("##########################################################\n\n");

printf("                --> APReS COMMUNICATION <-- \n\n");

for (itask = 0; itask<ntasks; itask++)

{

printf("Processus %d : Somme du vecteur reçu : %0.0f\n",

itask, buffsums[itask]);

}

printf("\n");

printf("##########################################################\n\n");

printf(" Temps total de communication : %f secondes\n\n", totaltime);

printf("##########################################################\n\n");

}

/*===============================================================*/

/* Libération de la mémoire                                      */

if (taskid == 0)

{

free(sendbuff[0]);

free(sendbuff);

}

else

{

free(sendbuff[0]);

free(sendbuff);

free(recvbuff);

}

/*===============================================================*/

/* Finalisation de MPI                                           */

MPI_Finalize();

Matrice A;

int  m, n;

/* ouvrir le fichier Matrices.dta sur le disque réseau pour la lecture */

FILE * aLire = fopen(NOM_A_LIRE, "r");

if (aLire == NULL)

{

printf("Le fichier n'existe pas");

}

else

{

fscanf(aLire, "%d%d\n", &m, &n);

////void lire(FILE * aLire, Matrice mat, int nbLigne, int nbCol)

for (int i = 0; i < m; i++) {

for (int j = 0; j < n; j++)

fscanf(aLire, "%d", &A[i][j]);

fscanf(aLire, "\n");

}

////void afficher(Matrice mat, char nom[], int nbLigne, int nbCol)

printf("\nContenu de la matrice de %d ligne(s) et %d colonne(s) :\n", m, n);

for (int i = 0; i < m; i++) {

for (int j = 0; j < n; j++)

printf("%d ", A[i][j]);

printf("\n");

}

printf("\n");

}

fclose(aLire);

}