Queue

Examples

Java

class Queue {
  Node first, last;

  void enqueue(Object item) {
    if (first == null) {
      last = new Node(item);
      first = last;
    } else {
      last.next = new Node(item);
    }
  }

  Node dequeue() {
    if (first != null) {
      Object item = first.data;
      first = first.next;
      return item;
    }
    return null;
  }
}