mpi example

Sure! Here is an example of MPI code in C:

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

int main(int argc, char argv) {
    MPI_Init(&argc, &argv);

    int rank, size;
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);

    printf("Hello from process %d of %d\n", rank, size);

    MPI_Finalize();
    return 0;
}

This is a simple MPI program that prints out the rank and size of each process. It demonstrates the basic usage of MPI functions like MPI_Init, MPI_Comm_rank, and MPI_Comm_size.