parallel1

#include <mpi.h>
#include <stdio.h>
#include <string>
#include <iostream>



using namespace std;
int main(int argc, char** argv) {

    // Initialize the MPI environment
    MPI_Init(&argc, &argv);

    // Get the number of processes
    int world_size;
    MPI_Comm_size(MPI_COMM_WORLD, &world_size);

    // Get the rank of the process
    int world_rank;
    MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
    char processor_name[MPI_MAX_PROCESSOR_NAME];
    int name_len;
    MPI_Get_processor_name(processor_name, &name_len);

    //// Print off a hello world message
    //printf("Hello world from processor %s, rank %d out of %d processors\n",
    //    processor_name, world_rank, world_size);


    switch (world_rank) {
    case 0: {
        int n = 123;
        MPI_Send(&n, 1, MPI_INT, 1, 0, MPI_COMM_WORLD);
        printf("The rank of the sending process: %d, The value being sent: %d\n", world_rank,n);
        break;
    }
    case 1: {
        int rec=2;

        cout << "Variable before receiving:" << rec << endl;
        MPI_Recv(&rec, 1, MPI_INT, 0, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
        printf("The rank of the recipient process: %d, Variable after receiving: %d\n", world_rank, rec);
        break;
    }
    default: {
        break;
    }
    }

    // Finalize the MPI environment.
    MPI_Finalize();
}