import java.util.concurrent.Semaphore;

public class Bufor {
    private int size = 40;
    private String[] data = new String[size];
    private int in;
    private int out;
    private int counter;
    private int endCount;
    private boolean end = false;
    static Semaphore elementy = new Semaphore(0);
    static Semaphore miejsca = new Semaphore(400);


    Bufor(int _end, Semaphore e, Semaphore m) {
        this.in = 0;
        this.out = 0;
        this.counter = 0;
        this.endCount = _end;
        this.elementy = e;
        this.miejsca = m;

    }

    public String get() {
        elementy.acquireUninterruptibly();
        if(counter >= endCount) {
            this.end = true;
            return "-1";
        }
        String temp = this.data[out];
        this.out = (this.out + 1) % size;
        miejsca.release();
        counter++;

        if(counter >= endCount) {
            this.end = true;
        }
        return temp;

    }

    public void add(String _data) {
        miejsca.acquireUninterruptibly();
        data[in] = _data;
        in = (in + 1) % size;
        elementy.release();
    }

    public synchronized boolean check(){
        if(this.end){
            return true;
        }
        return false;
    }
}