#include <pthread.h>
#include <stdlib.h>
#include <stdio.h>
#define S 5
#define C 5
#define CSLEEP 2
#define SSLEEP 3

pthread_t tid[C + S];
int c[C], s[S], nt[C + S];
pthread_mutex_t mutcond, exclusafis;
pthread_cond_t cond;
int cititori;

//afiseaza starea curenta a cititorilor si scriitorilor
void afiseaza() {
    int i;
    pthread_mutex_lock(&exclusafis);
    for (i = 0; i < C; i++) printf("C%d_%d\t",i, c[i]);
    for (i = 0; i < S; i++) printf("S%d_%d\t",i, s[i]);
    printf("\n");
    fflush(stdout);
    pthread_mutex_unlock(&exclusafis);
}

//rutina thread cititor
void* cititor(void* nrc) {
    int indc = *(int*)nrc;
    for ( ; ; ) {
        c[indc] = -1; // Asteapta sa citeasca

        pthread_mutex_lock(&mutcond);
        cititori++;
        c[indc] = 0; // Citeste
        afiseaza();
        pthread_mutex_unlock(&mutcond);
        sleep(1 + rand() % CSLEEP);
        c[indc] = -2; // A citit si doarme
        pthread_mutex_lock(&mutcond);
        cititori--;
        pthread_cond_signal(&cond);
        pthread_mutex_unlock(&mutcond);

        sleep(1 + rand() % CSLEEP);
    }
}

void* scriitor (void* nrs) {
    int inds = *(int*)nrs;
    for ( ; ; ) {
        s[inds] = -1; // Asteapta sa scrie
        
        pthread_mutex_lock(&mutcond);
        for ( ; cititori > 0; ) {
            pthread_cond_wait(&cond, &mutcond);
        }
        s[inds] = 0; // Scrie
        afiseaza();
        sleep(1 + rand() % SSLEEP);
        s[inds] = -2; // A scris si doarme
        pthread_mutex_unlock(&mutcond);

        sleep(1 + rand() % SSLEEP);
    }
}

//functia principala "main"    
main() {
    pthread_mutex_init(&exclusafis, NULL);
    pthread_mutex_init(&mutcond, NULL);
    pthread_cond_init(&cond, NULL);
    int i;
    for (i = 0; i < C; c[i] = -3, nt[i] = i, i++); // -3 : Nu a pornit
    for (i = 0; i < S; s[i] = -3, nt[i + C] = i, i++);
    
    for (i = 0; i < C; i++) pthread_create(&tid[i], NULL, cititor, &nt[i]);
    for (i = C; i < C + S; i++) pthread_create(&tid[i], NULL, scriitor, &nt[i]);

    for (i = 0; i < C + S; i++) pthread_join(tid[i], NULL);

    pthread_cond_destroy(&cond);
    pthread_mutex_destroy(&mutcond);
    pthread_mutex_destroy(&exclusafis);
}