// online source: http://d3s.mff.cuni.cz/~ceres/sch/mwy/text/ch07s08s05.html
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <mpi.h>

int main (int iArgC, char *apArgV [])
{
    int iOutput;
    int iInput;
    int iRank;
    
    MPI_Init (&iArgC, &apArgV);
    MPI_Comm_rank (MPI_COMM_WORLD, &iRank);
    if (iRank == 0) iInput = 1;
    else iInput = iRank;
    MPI_Scan (&iInput, &iOutput, 1, MPI_INT, MPI_PROD, MPI_COMM_WORLD);
    printf ("Process %d: Factorial %d\n", iRank, iOutput);
    MPI_Finalize ();
    
    return (0);
}