//#include "mpi.h"
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

#define MAXSIZE 1000

int main(int argc, char **argv)
{
    int myid, numprocs;
    int data[MAXSIZE], i, x, low, high, myresult, result;
    char filename[255];
    FILE *fileptr;
    int eofmarker;

//    MPI_Init(&argc, &argv);
//    MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
//    MPI_Comm_rank(MPI_COMM_WORLD, &myid);

//    if(myid == 0 ) {
//      strcpy(filename, getenv("HOME"));
//      strcat(filename, "/SuperComp2006/nums.txt");
      strcpy(filename, "nums.txt");
      if ((fileptr = fopen(filename, "r")) == NULL) {
        printf("Can't open the input file: %s\n\n", filename);
        exit(1);
      }
      i = 0;
// see http://www.sci.brooklyn.cuny.edu/~jones/CIS1.5/fromfile.html

      eofmarker = fscanf(fileptr, "%d", &data[i]);
      while (eofmarker != EOF && i < MAXSIZE) {
        i++;
        eofmarker = fscanf(fileptr, "%d", &data[i]);
      }
      printf("%d\n", i);
//    }
//  Broadcast data

//  Add this processor's section of the array
    result = 0;
    numprocs = 4;
    x = MAXSIZE/numprocs;
    myid = 0;
    low = myid*x;
    high = low + x;
    myresult = 0;
    for(i = low; i < high; i++)
       myresult += data[i];
    printf("Process %d, Sum = %d\n", myid, myresult);
    result += myresult;

    myid = 1;
    low = myid*x;
    high = low + x;
    myresult = 0;
    for(i = low; i < high; i++)
       myresult += data[i];
    printf("Process %d, Sum = %d\n", myid, myresult);
    result += myresult;

    myid = 2;
    low = myid*x;
    high = low + x;
    myresult = 0;
    for(i = low; i < high; i++)
       myresult += data[i];
    printf("Process %d, Sum = %d\n", myid, myresult);
    result += myresult;
  
    myid = 3;
    low = myid*x;
    high = low + x;
    myresult = 0;
    for(i = low; i < high; i++)
       myresult += data[i];
    printf("Process %d, Sum = %d\n", myid, myresult);
    result += myresult;

//  Compute global sum
    printf("Process 0, total sum = %d\n", result);

//    MPI_Finalize();
    return 0;
}

/*

mpirun -np 4 a.out 
1000
Process 0, Sum = 127769
Process 1, Sum = 123735
Process 2, Sum = 131857
Process 0, total sum = 510653
Process 3, Sum = 127292

*/