package data_structures_java ;
import java.util.Iterator;
import java.util.PriorityQueue ;
import java.util.* ;
public class Queue_implementation {

    PriorityQueue<Integer> actual_queue ;

    public Queue_implementation(){
        actual_queue = new PriorityQueue<Integer>() ;

    }

    public  void add(int num){
        actual_queue.add(num) ;
    }

    public int remove(){
          return actual_queue.remove() ;
    }

    public int peek(){
        if( actual_queue.isEmpty()) return -1 ;
        else return actual_queue.peek() ;
    }

    public int element(){
        return actual_queue.element() ;
    }

    public void print_queue(){
        PriorityQueue<Integer>copy = new PriorityQueue<Integer>();
        copy.addAll(actual_queue) ;
        Iterator<Integer> through = actual_queue.iterator() ;
        while(through.hasNext() ) {
                System.out.print(through.next() + " ") ;
        }
        System.out.println() ;

        actual_queue.addAll(copy) ;

    }
    public static void main(String[] args) {
        Queue_implementation x = new Queue_implementation() ;
        x.add(10) ;
        x.add(9) ;
        x.add(8) ;
        x.add(7) ;
        x.add(6) ;
        x.print_queue() ;
    }

}

Object[] queue_object_array = x.toArray() ;
Arrays.sort(queue_object_array) ;

System.out.println(Arrays.toString(priorityQueue.toArray()));

Object[] arr = priorityQueue.toArray();