data_structures_free

net/datastructures/Stack.java

@@ -0,0 +1,44 @@
+package net.datastructures;
+//begin#fragment Stack
+ /** 
+  * Interface for a stack: a collection of objects that are inserted
+  * and removed according to the last-in first-out principle.  This
+  * interface includes the main methods of java.util.Stack.
+  * 
+  * @author Roberto Tamassia
+  * @author Michael Goodrich
+  * @see EmptyStackException
+  */
+
+public interface Stack<E> {
+ /**
+  * Return the number of elements in the stack.
+  * @return number of elements in the stack. 
+  */
+  public int size();
+ /** 
+  * Return whether the stack is empty.
+  * @return true if the stack is empty, false otherwise. 
+  */
+  public boolean isEmpty();
+ /** 
+  * Inspect the element at the top of the stack.
+  * @return top element in the stack.  
+  * @exception EmptyStackException if the stack is empty. 
+  */
+  public E top() 
+    throws EmptyStackException;  
+ /**
+  * Insert an element at the top of the stack.
+  * @param element to be inserted.
+  */
+  public void push (E element); 
+ /** 
+  * Remove the top element from the stack.
+  * @return element removed.
+  * @exception EmptyStackException if the stack is empty.
+  */
+  public E pop()
+    throws EmptyStackException; 
+}
+//end#fragment Stack