import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.CountDownLatch;

public class MinstCB {
    public static void main(String[ ] args) {
        new MinstCB();
    }
    int [ ] tabell; 
    MinstMonitorCB monitor;  
    Runnable runAbl; 
    final int antallTrader = 64;
    CountDownLatch bariere = new CountDownLatch(antallTrader);
    public MinstCB ( ) {     
        tabell = new int[6400000];
	    for (int in = 0; in< 6400000; in++)  {
		    tabell[in] = (int)Math.round(Math.random()* Integer.MAX_VALUE);
		}
	    monitor = new MinstMonitorCB();
	    for (int i = 0; i< 64; i++)  {
            runAbl = new MinstTradCB(tabell,i*100000,((i+1)*100000)-1,monitor,bariere);
            new Thread(runAbl).start();
        }
	    try { 
	        bariere.await();
            System.out.println("Minste verdi var: " + monitor.hentMinste());
	    }
	    catch (InterruptedException ex){ 
	        System.out.println(" Uventet avbrudd ");  System.exit(0); 
	    }  
    }
}

class MinstMonitorCB {
    private Lock laas = new ReentrantLock();
    int minstTilNa = Integer.MAX_VALUE;
    int antallFerdigeSubtrader = 0;
    public void giMinsteVerdi (int minVerdi) {
       laas.lock();
       try {
          if(minstTilNa > minVerdi) minstTilNa = minVerdi;
       }
       finally { 
          laas.unlock();  
       }
    }
    public int hentMinste () {return minstTilNa;}  //Trenger ikke laases
                                       // fordi alle andre operasjoner er ferdige
}

class MinstTradCB implements Runnable {
    int [ ] tab; int startInd, endInd;
    MinstMonitorCB mon;  
    CountDownLatch bariere;
    MinstTradCB(int [ ] tb, int st, int en, MinstMonitorCB m, CountDownLatch bariere) {
        tab = tb; startInd = st; endInd = en;
        mon = m; this.bariere = bariere;
    }
    public void run(){
        int minVerdi = Integer.MAX_VALUE;     
        for (int ind = startInd; ind <= endInd; ind++) {
                if(tab[ind] < minVerdi) minVerdi = tab[ind];  
        }
        mon.giMinsteVerdi(minVerdi);
        bariere.countDown();
    } 
}