data_structures_free

net/datastructures/Deque.java

@@ -0,0 +1,45 @@
+package net.datastructures;
+//begin#fragment Deque
+ /** 
+  * Interface for a deque: a collection of objects that are inserted
+  * and removed at both ends; a subset of java.util.LinkedList methods.
+  * 
+  * @author Roberto Tamassia
+  * @author Michael Goodrich
+  */
+
+public interface Deque<E> {
+ /**
+  * Returns the number of elements in the deque.
+  */
+  public int size();
+ /** 
+  * Returns whether the deque is empty.
+  */
+  public boolean isEmpty();
+ /** 
+  * Returns the first element; an exception is thrown if deque is empty.
+  */
+  public E getFirst() throws EmptyDequeException;
+ /** 
+  * Returns the last element; an exception is thrown if deque is empty.
+  */
+  public E getLast() throws EmptyDequeException;
+ /**
+  * Inserts an element to be the first in the deque.
+  */
+  public void addFirst (E element); 
+ /**
+  * Inserts an element to be the last in the deque.
+  */
+  public void addLast (E element); 
+ /** 
+  * Removes the first element; an exception is thrown if deque is empty.
+  */
+  public E removeFirst() throws EmptyDequeException;
+ /** 
+  * Removes the last element; an exception is thrown if deque is empty.
+  */
+  public E removeLast() throws EmptyDequeException;
+}
+//end#fragment Deque