tasks a-s

Task/Queue-Definition/Java/queue-definition.java

@@ -0,0 +1,40 @@
+public class Queue<E>{
+	Node<E> head = null, tail = null;
+
+	static class Node<E>{
+		E value;
+		Node<E> next;
+
+		Node(E value, Node<E> next){
+			this.value= value;
+			this.next= next;
+		}
+
+	}
+
+	public Queue(){
+	}
+
+	public void enqueue(E value){ //standard queue name for "push"
+		Node<E> newNode= new Node<E>(value, null);
+		if(empty()){
+			head= newNode;
+		}else{
+			tail.next = newNode;
+		}
+		tail= newNode;
+	}
+
+	public E dequeue() throws java.util.NoSuchElementException{//standard queue name for "pop"
+		if(empty()){
+			throw new java.util.NoSuchElementException("No more elements.");
+		}
+		E retVal= head.value;
+		head= head.next;
+		return retVal;
+	}
+
+	public boolean empty(){
+		return head == null;
+	}
+}