/*
I certify that this program is entirely my own work and none of it is the work of any other person.
    George Aparicio
Write an MPI program, countprimes which will count the number of prime numbers in the numbers
from 1 to n inclusive where n is a long integer. The value for n which can be set in the program using
a constant should be 50,000.
*/
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <mpi.h>
#define range 50000

int findprimes(int id, long n)
{
    int i;
if(n == 0 || n == 1)
{
    return 0;
}
else
{
    for(i = 2; i < n/2; i++){
        if(n % i == 0)
        {
            return 0;
        }
    }
}
    printf("Process %d) Prime Number: 5d\n", id, n);//prints if it passes
    fflush(stdout);
    return 1;
}
//it would have the timer, the total number of primes and rank and number
int main(int argc, char *argv[])
{
    int id, p;
    int total, global;
    double time;
    long i;
    const long prime = 50000;

    MPI_Init(&argc, &argv);
    //begins
    MPI_Comm_rank(MPI_COMM_WORLD, &id);
    MPI_Comm_size(MPI_COMM_WORLD, &p);

    MPI_Barrier(MPI_COMM_WORLD);
    time -= MPI_Wtime();

    total = 0;
    for(i = id; i < range; i += p)
    {
        total += findprimes(id, i);
    }
    MPI_Reduce(&total, &global, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);

    time += MPI_Wtime();
    //ends
    if(!id){
        printf("Runtime %0.6f\n", time);
        fflush(stdout);
    }
    MPI_Finalize();

    if(!id)
    {
        printf("There is %d total prime.\n", global);

    }
    return 0;
}