#include <stdio.h>
#include <mpi.h>
#include <stdlib.h>
#include <time.h>
#include <malloc.h>
#define Products 10

int main(int argc, char **argv )
 {
  int myid,numprocs;
  int true = 1;
  int false = 0;
  int messages = true;
  int i,g,items,flag;
  int *customer_items;
  int checked_out = 0;
  /* Note, Products below are defined in order of increasing weight */
  char Groceries[Products][20] = {"Chips","Lettuce","Bread","Eggs","Pork Chops","Carrots","Rice","Canned Beans","Spaghetti Sauce","Potatoes"};
  MPI_Status status;

  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
  MPI_Comm_rank(MPI_COMM_WORLD,&myid);
  if (numprocs >= 2)
   {
    if (myid == 0) // Master
     {
      customer_items = (int *) malloc(numprocs * sizeof(int));
      /* initialize customer items to zero - no items received yet */
      for (i=1;i<numprocs;i++) customer_items[i]=0;
      while (messages)
       {
        MPI_Iprobe(MPI_ANY_SOURCE,MPI_ANY_TAG,MPI_COMM_WORLD,&flag,&status);
        if (flag)
         {
          MPI_Recv(&items,1,MPI_INT,status.MPI_SOURCE,status.MPI_TAG,MPI_COMM_WORLD,&status);
	  /* increment the count of customer items from this source */
          customer_items[status.MPI_SOURCE]++;
          if (customer_items[status.MPI_SOURCE] == items) checked_out++; 
          printf("%d: Received %20s from %d, item %d of %d\n",myid,Groceries[status.MPI_TAG],status.MPI_SOURCE,customer_items[status.MPI_SOURCE],items);
         }
        if (checked_out == (numprocs-1)) messages = false;
       }
     } // Master 
    else  // Workers
     {
      srand((unsigned)time(NULL)+myid);
      items = (rand() % 5) + 1;
      for(i=1;i<=items;i++)
       {
        g = rand() % 10;
        printf("%d: Sending %s, item %d of %d\n",myid,Groceries[g],i,items);
        MPI_Send(&items,1,MPI_INT,0,g,MPI_COMM_WORLD);
       }       
     } // Workers
   }
  else
   printf("ERROR: Must have at least 2 processes to run\n");

  MPI_Finalize();
  return 0;
 }