#include <mpi.h>
#include <stdio.h>
int main(int argc, char **argv)
{
    int rank, size;
    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    if ( rank == 0 ) {
        /* Rank 0 sends an integer to each of the other process ranks */
        int i;
        int value = 0;
        for (i = 1; i < size; i++) {
            value = value + i;
            MPI_Send(&value, 1, MPI_INT, i, 0, MPI_COMM_WORLD);
        }
    }
    else {
        /* All other process ranks receive one number from Rank 0 */
        int value;
        MPI_Status status;
        MPI_Recv(&value, 1, MPI_INT, 0, 0, MPI_COMM_WORLD, &status);
        printf("Rank %d received value %d\n", rank, value);
    }
    MPI_Finalize();
    return 0;
}