#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

int Account[3];
sem_t semaphore1;
sem_t semaphore2;
sem_t semaphore3;


void *thread1(void *vargp){
  int i, internal_reg;

  /*synch with thread2, thread3, and thread 4 */

  for(i = 0; i < 10000; i++){

      sem_wait(&semaphore1);
      internal_reg = Account[0];
      internal_reg = internal_reg - 200;
      Account[0] = internal_reg;
      sem_post(&semaphore1);

      sem_wait(&semaphore1);
      internal_reg = Account[1];
      internal_reg = internal_reg + 200;
      Account[1] = internal_reg;
      sem_post(&semaphore1);

      if((i+1)% 1000 == 0){

      }
  }
}



int main(){

  Account[0] = 100000;
  Account[1] = 100000;
  Account[2] = 100000;

  sem_init(&semaphore1, 0, 1);
  sem_init(&semaphore2, 0, 1);
  sem_init(&semaphore3, 0, 1);


  pthread_t tid[4];
  pthread_create(&tid[0], NULL, thread1, NULL);
  pthread_create(&tid[1], NULL, thread2, NULL);
  pthread_create(&tid[2], NULL, thread3, NULL);
  pthread_create(&tid[3], NULL, thread4, NULL);
  pthread_join(&tid[1], NULL);

}