4. labor. Félreértett 6. feladat kijavítva

4. labor/PQueue/src/PQueue.java

+/*
+In computer science, a priority queue is an abstract data type which is 
+like a regular queue or stack data structure, but where additionally each element 
+has a "priority" associated with it. In a priority queue, an element with high priority 
+is served before an element with low priority. If two elements have the same priority, 
+they are served according to their order in the queue.
+https://en.wikipedia.org/wiki/Priority_queue
+*/
+
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -18,14 +27,13 @@ public class PQueue <T extends Comparable> implements Iterable<T>{
 	void push (T t)
 	{
 		f.add(t);
-		Collections.sort(f);
 	}
 	
 	T top()
 	{
 		if(size()<1)
 			throw new EmptyQueueException("Nincs elem a listában");
-		return f.get(size()-1);
+		return (T) Collections.max(f);
 	}
 	
 	T pop()
@@ -41,6 +49,7 @@ public class PQueue <T extends Comparable> implements Iterable<T>{
 	}
 
 	public Iterator<T> iterator() {
+		Collections.sort(f, new ReverseComparator<T>());
 		return f.iterator();
 	}
 }

4. labor/PQueue/src/ReverseComparator.java

+
+import java.util.Comparator;
+
+
+public class ReverseComparator<T extends Comparable> implements Comparator<T>{
+
+	public int compare(T t, T t1) {
+		return -1*t.compareTo(t1);
+	}
+	
+}

4. labor/PQueue/src/Test.java

@@ -12,7 +12,16 @@ public class Test {
 		}
 		System.out.println(q.size());
 		System.out.println(q.pop());
-		System.out.println(q.top());		
+		System.out.println(q.pop());	
+		System.out.println(q.pop());
+//		System.out.println(q.pop());//exceptiont dobna ami nekünk most jó
+
+		PQueue<Integer> s = new PQueue<>();
+		s.push(1); s.push(2); s.push(3); s.push(4);
+		for (Integer i : s) {
+			System.out.println(i);
+		}
+
 	}
 	
 }