L4Ex4.cpp

#include <mpi.h>
#include <stdio.h>
#include <stdlib.h>

// В зависимости от варианта а или б поменять строки 60-75
int main(int argc, char *argv[])
{
    int numtask, sendcount, reccount, source;
    double *Matr_Init, *Matr_Fin;
    int i, myrank, root = 0;

    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
    MPI_Comm_size(MPI_COMM_WORLD, &numtask);
    MPI_Status status;
    MPI_Request req;
    double Rows[numtask], Rows_Init[numtask];
    sendcount = numtask;
    reccount = numtask;

    if (myrank == 0)
    {
        printf("\n=====REZULTATUL PROGRAMULUI '%s' \n", argv[0]);
    }

    MPI_Barrier(MPI_COMM_WORLD);

    //Procesul cu rankul root aloca spatiul si initializeaza matrice
    if (myrank == root)
    {
        Matr_Init = (double *)malloc(numtask * numtask * sizeof(double));
        Matr_Fin = (double *)malloc(numtask * numtask * sizeof(double));

        for (int i = 0; i < numtask * numtask; i++)
        {
            Matr_Init[i] = rand() / 1000000000.0;
        }

        printf("Tipar datele initiale\n");

        for (int i = 0; i < numtask; i++)
        {
            printf("\n");
            for (int j = 0; j < numtask; j++)
            {
                printf("Matr_Init[%d,%d]=%5.2f ", i, j, Matr_Init[i * numtask + j]);
            }
        }

        printf("\n");
        MPI_Barrier(MPI_COMM_WORLD);
    }
    else
    {
        MPI_Barrier(MPI_COMM_WORLD);
    }

    //MPI_Scatter(Matr_Init, sendcount, MPI_DOUBLE, Rows, reccount, MPI_DOUBLE, root, MPI_COMM_WORLD);

    if (myrank == root)
    {

        for (int i = 0; i < numtask; i++)
        {
            MPI_Sendrecv(&Matr_Init[i * numtask], numtask, MPI_DOUBLE, i, 1,
                         Rows, numtask, MPI_DOUBLE, i, 1, MPI_COMM_WORLD, &status);
        }
    }
    else
    {
        MPI_Sendrecv(NULL, 0, MPI_DOUBLE, 0, 1,
                     Rows, numtask, MPI_DOUBLE, 0, 1, MPI_COMM_WORLD, &status);
    }

    MPI_Barrier(MPI_COMM_WORLD);

    printf("\n");
    printf("--->Result of function MPI_Scatter via MPI_Recv and MPI_Send for process with rank %d \n", myrank);
    for (i = 0; i < numtask; ++i)
    {
        printf("Rows[%d]=%5.2f ", i, Rows[i]);
    }

    printf("\n");
    MPI_Barrier(MPI_COMM_WORLD);

    // MPI_Gather(Rows, sendcount, MPI_DOUBLE, Matr_Fin, reccount, MPI_DOUBLE, root, MPI_COMM_WORLD);

    for (int i = 0; i < numtask; i++)
    {
        MPI_Send(&Rows[i], 1, MPI_DOUBLE, 0, 10, MPI_COMM_WORLD);
    }

    if (myrank == root)
    {
        for (int i = 0; i < numtask; i++)
        {
            for (int j = 0; j < numtask; j++)
            {
                MPI_Recv(&Matr_Fin[i * numtask + j], 1, MPI_DOUBLE, i, 10, MPI_COMM_WORLD, &status);
            }
        }
    }

    MPI_Barrier(MPI_COMM_WORLD);

    if (myrank == root)
    {
        printf("\n--->Result of function MPI_Gather via MPI_Recv and MPI_Send");
        for (int i = 0; i < numtask; i++)
        {
            printf("\n");
            for (int j = 0; j < numtask; j++)
            {
                printf("Matr_Fin[%d,%d]=%5.2f ", i, j, Matr_Fin[i * numtask + j]);
            }
        }
    }
    printf("\n");

    MPI_Finalize();
    return 0;
}