int main(int argc, char **argv)
{
    int rank, size;
    char message[100];
 
    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
 
    if (size < 2)
    {
        fprintf(stderr, "This program requires at least 2 MPI processes\n");
        MPI_Abort(MPI_COMM_WORLD, 1);
    }
 
    if (rank == 0)
    {
        // Process 0 sends a message to Process 1
        strcpy(message, "Hello from process 0");
        MPI_Send(message, strlen(message) + 1, MPI_CHAR, 1, 0, MPI_COMM_WORLD);
    }
    else if (rank == 1)
    {
        // Process 1 receives the message from Process 0
        MPI_Recv(message, 100, MPI_CHAR, 0, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
        printf("Received message on process 1: %s\n", message);
    }
 
    MPI_Finalize();
    return 0;
}
 

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