Programming

#include <stdio.h>
#include <pthread.h>
#include <malloc.h>
#include <stdlib.h>
#include <time.h>
#define N 5

  pthread_mutex_t  *mymutex;

void think (void *arg) {
        int i,*id;
        int j;
        id = (int *) arg;
        i = *id;
        j = 2+rand()%N; 
      /*  sleep(j);*/
	printf("\nPhilosopher  %d is thinking for %d seconds\n", i,j);
               
}

void eat (void *arg) {
        int i,*id;
        int j;
        id = (int *) arg;
        i = *id;
        j = 3+rand()%N;
        
	printf ("\nPhilosopher  %d is eating for %d seconds\n", i,j);
	sleep(j);
}

void *philosopher (void * arg)
{
   while(1) {    
      int i,j;
      i = *(int *) arg;
      j = rand()%N+3;
              think( arg);  
                if (i%2 == 1) {
              pthread_mutex_unlock(&mymutex[(i+1)%N]);    
              pthread_mutex_unlock(&mymutex[(i)%N]);
              printf("philosopher %d is eating for %d seconds\n",i,j);
              fflush(stdout);
              sleep(j); 
/*              printf("philosopher %d is no longer eating\n",i);
*/              pthread_mutex_lock(&mymutex[(i)%N]);   
              pthread_mutex_lock(&mymutex[(i+1)%N]);
            
           }
              else
                         {
              pthread_mutex_unlock(&mymutex[(i)%N]);     
              pthread_mutex_unlock(&mymutex[(i+1)%N]); 
              printf("philosopher %d is eating for %d seconds\n",i,j);
              fflush(stdout);
              sleep(j);
 /*             printf("philosopher %d is no longer eating\n",i);
*/              pthread_mutex_lock(&mymutex[(i+1)%N]);  
              pthread_mutex_lock(&mymutex[(i)%N]);   
             
            
           }
          /*   pthread_exit(NULL);   */
   }
}
   
void main (int argc, char*argv[]) {
        int rc, i, *ids;
        int status;
        
        pthread_t threads[N];
        pthread_attr_t attr;
        mymutex = (pthread_mutex_t*)malloc(sizeof(mymutex) * N);
        ids = (int *) malloc(sizeof(int)*N); 
        
        for (i = 0; i<N; i++) {
             	pthread_mutex_init(&mymutex[i], NULL);
             }
        pthread_attr_init(&attr);
        pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
        for (i = 0; i<N; i++) {
        ids[i] = i; 
  rc = pthread_create(&threads[i], NULL, philosopher,(void*)&ids[i]);
        if (rc) {
           printf("ERROR;return code from pthread_create() is %d\n",rc);
           exit(-1);
          }
	}
        pthread_attr_destroy(&attr);
        for (i = 0; i<N; i++) {
           pthread_mutex_destroy(&mymutex[i]);
        } 
        pthread_exit(NULL);
}

.......
pthread_mutex_unlock(&mymutex[(i+1)%N]);    
              pthread_mutex_unlock(&mymutex[(i)%N]);
              printf("philosopher %d is eating for %d seconds\n",i,j);
              fflush(stdout);
              sleep(j); 
             printf("philosopher %d is no longer eating\n",i);
             pthread_mutex_lock(&mymutex[(i)%N]);   
              pthread_mutex_lock(&mymutex[(i+1)%N]);
.......