task6.cpp

#include <iostream>
#include "mpi.h"

int main(int argc, char** argv) {
    MPI_Status status;
    int rank, size, message_size;
    int const count = 18;
    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    if (rank == 0) {
        int x[count], y[count];
        printf("Vector\nx y\n");
        for (int i = 0; i < count; i++) {
            x[i] = rand() % 100;
            printf("%d ", x[i]);
            y[i] = rand() % 100;
            printf("%d\n", y[i]);
        }
        for (int i = 1; i < size; i++) {
            MPI_Send(x + (i - 1) * count / (size - 1), count / (size - 1), MPI_INT, i, 1, MPI_COMM_WORLD);
            MPI_Send(y + (i - 1) * count / (size - 1), count / (size - 1), MPI_INT, i, 2, MPI_COMM_WORLD);
        }
    } else {
        MPI_Probe(0, 1, MPI_COMM_WORLD, &status);
        MPI_Get_count(&status, MPI_INT, &message_size);
        int* recv_x = (int*)malloc(sizeof(int) * message_size);
        MPI_Recv(recv_x, message_size, MPI_INT, 0, 1, MPI_COMM_WORLD, &status);

        MPI_Probe(0, 2, MPI_COMM_WORLD, &status);
        MPI_Get_count(&status, MPI_INT, &message_size);
        int* recv_y = (int*)malloc(sizeof(int) * message_size);
        MPI_Recv(recv_y, message_size, MPI_INT, 0, 2, MPI_COMM_WORLD, &status);

        int* z = (int*)malloc(sizeof(int) * message_size);
        for (int i = 0; i < message_size; i++) {
            z[i] = recv_x[i] + recv_y[i];
        }
        MPI_Send(z, message_size, MPI_INT, 0, 0, MPI_COMM_WORLD);
    }

    if (rank == 0) {
        int result[count];
        int pointer = 0;

        for (int i = 1; i < size; i++) {
            MPI_Probe(i, 0, MPI_COMM_WORLD, &status);
            MPI_Get_count(&status, MPI_INT, &message_size);
            int* z = (int*)malloc(sizeof(int) * message_size);
            MPI_Recv(z, message_size, MPI_INT, i, 0, MPI_COMM_WORLD, &status);
            for (int j = 0; j < message_size; j++) {
                result[pointer] = z[j];
                pointer++;
            }
        }

        printf("Result z vector is : \n");
        for (int i = 0; i < count; i++) {
            printf("%d ", result[i]);
        }
        printf("\n");
    }

    MPI_Finalize();
}