#include <stdio.h>
#include <unistd.h>

/*
 * NUMPROC - Number of processes to run including parent process
 *
 * ie: NUMPROC-1 children will be spawned
 *
 */
#define NUMPROC 4

/*
 * The Message Structure
 */
struct msg {
  int iFrom;   /* Who sent the message */
  int wType;   /* -1=termination, 0=request, 1=result, 2=additional request */
  int wVal1;   /* initial value in range */
  int wVal2;   /* final value in range */
  int wTotal;  /* total of all numbers in range (Max Range in add. mode) */
};

/*
 * Semaphore ID array
 *
 * 2*ID   = Send
 * 2*ID+1 = Receive
 *
 */
int semid[2*NUMPROC];

/*
 * Mailboxes for all processes
 */
struct msg *inbox[NUMPROC];