structure
Class AbstractStack

java.lang.Object
  |
  +--structure.AbstractStructure
        |
        +--structure.AbstractLinear
              |
              +--structure.AbstractStack

All Implemented Interfaces:

Linear, Stack, Structure

Direct Known Subclasses:

StackArray, StackList, StackVector

public abstract class AbstractStack

extends AbstractLinear

implements Stack

An abstract structure implementing features common to all Last-In, First-Out structures in this package. Stacks are typically used to store the state of a recursively solved problem. The structure package provides several extensions of the AbstractStack class, each of which has its particular strengths and weaknesses.

Example usage:

To reverse a string using a stack, we would use the following:

 public static void main(String[] arguments)
 {
     if(arguments.length > 0){
	   AbstractStack reverseStack = new StackList();
	   String s = arguments[0];
	    
	   for(int i=0; i < s.length(); i++){
	       reverseStack.push(new Character(s.charAt(i)));
	   }

	   while(!reverseStack.AbstractLinear.empty()){
	       System.out.print(reverseStack.pop());
	   }

	   System.out.println();
     }
 }
 

See Also:

Stack, StackVector, StackList, StackArray

Constructor Summary

AbstractStack()

Method Summary

Object	getFirst() Deprecated. Please use method get, rather than getFirst!
Object	peek() Fetch a reference to the top element of the stack.
Object	pop() Remove an element from the top of the stack.
void	push(Object item) Add an element from the top of the stack.

Methods inherited from class structure.AbstractLinear

empty, remove

Methods inherited from class structure.AbstractStructure

contains, elements, hashCode, isEmpty, values

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, notify, notifyAll, registerNatives, toString, wait, wait, wait

Methods inherited from interface structure.Stack

add, empty, get, remove, size

Methods inherited from interface structure.Structure

clear, contains, elements, isEmpty, iterator, remove, values

Constructor Detail

AbstractStack

public AbstractStack()

Method Detail

push

public void push(Object item)

Add an element from the top of the stack.

Specified by:

push in interface Stack

Parameters:

item - The element to be added to the stack top.

Postcondition:

item is added to stack will be popped next if no intervening add

pop

public Object pop()

Remove an element from the top of the stack.

Specified by:

pop in interface Stack

Precondition:

stack is not empty

Postcondition:

most recently added item is removed and returned

Returns:

The item removed from the top of the stack.

getFirst

public Object getFirst()

Deprecated. Please use method get, rather than getFirst!

Fetch a reference to the top element of the stack.

Specified by:

getFirst in interface Stack

Precondition:

stack is not empty

Postcondition:

top value (next to be popped) is returned

Returns:

A reference to the top element of the stack.

peek

public Object peek()

Fetch a reference to the top element of the stack. Provided for compatibility with java.util.Stack.

Specified by:

peek in interface Stack

Precondition:

stack is not empty

Postcondition:

top value (next to be popped) is returned

Returns:

A reference to the top element of the stack.