structure
Class StackArray

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

All Implemented Interfaces:

Linear, Stack, Structure

public class StackArray

extends AbstractStack

implements Stack

An implementation of a stack, based on array. The head of the stack is stored in the first position of the array, allowing the stack to grow and shrink in constant time. This stack implementation is ideal for applications that require a stack with a known maximum size that expands in constant time.

Example usage:

To reverse a string, we would use the following:

 public static void main(String[] arguments)
 {
     if(arguments.length > 0){
         StackArray reverseStack = new StackArray(arguments[0].length());
	   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.AbstractStack.pop());
	   }

	   System.out.println();
     }
 }
 

See Also:

Stack, StackVector, StackList, AbstractStack

Field Summary

protected Object[]	data The array of value references.
protected int	top An index to the top element of the stack.

Constructor Summary

StackArray(int size)
Construct a stack capable of holding at least size elements.

Method Summary

void	add(Object item) Add a value to the top of the stack.
void	clear() Remove all elements from the stack.
Object	get() Get a reference to the top value in the stack.
boolean	isEmpty() Determine if the stack is empty.
boolean	isFull() Determine if the stack is full.
Iterator	iterator() Returns an iterator for traversing the structure.
Object	remove() Remove a value from the top of the stack.
int	size() Determine the number of elements in the stack.
String	toString() Construct a string representation of the stack.

Methods inherited from class structure.AbstractStack

getFirst, peek, pop, push

Methods inherited from class structure.AbstractLinear

empty, remove

Methods inherited from class structure.AbstractStructure

contains, elements, hashCode, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface structure.Stack

empty, getFirst, peek, pop, push

Methods inherited from interface structure.Structure

contains, elements, remove, values

Field Detail

top

protected int top

An index to the top element of the stack.

data

protected Object[] data

The array of value references. Top of the stack is higher in array.

Constructor Detail

StackArray

public StackArray(int size)

Construct a stack capable of holding at least size elements.

Parameters:

size - The maximum size of the stack.

Method Detail

clear

public void clear()

Remove all elements from the stack.

Specified by:

clear in interface Structure

Postcondition:

removes all elements from stack

add

public void add(Object item)

Add a value to the top of the stack.

Specified by:

add in interface Stack

Parameters:

item - The value to be added.

Postcondition:

adds an element to stack; Will be next element popped if no intervening push

See Also:

AbstractStack.push(java.lang.Object)

remove

public Object remove()

Remove a value from the top of the stack.

Specified by:

remove in interface Stack

Precondition:

stack is not empty

Postcondition:

removes and returns the top element from stack;

Returns:

The value removed from the top of the stack.

See Also:

AbstractStack.pop()

get

public Object get()

Get a reference to the top value in the stack.

Specified by:

get in interface Stack

Precondition:

stack is not empty

Postcondition:

returns the top element (most recently pushed) from stack

Returns:

A reference to the top element of the top of the stack.

iterator

public Iterator iterator()

Description copied from interface: Structure

Returns an iterator for traversing the structure.

Specified by:

iterator in interface Structure

Following copied from interface: structure.Structure

Returns:

an iterator for traversing the structure

See Also:

AbstractIterator, Iterator, Enumeration, Structure.elements()

size

public int size()

Determine the number of elements in the stack.

Specified by:

size in interface Stack

Postcondition:

returns the size of the stack

Returns:

The number of values within the stack.

isEmpty

public boolean isEmpty()

Determine if the stack is empty.

Specified by:

isEmpty in interface Structure

Overrides:

isEmpty in class AbstractStructure

Postcondition:

returns true iff the stack is empty

Returns:

True iff the stack is empty.

See Also:

AbstractLinear.empty()

isFull

public boolean isFull()

Determine if the stack is full.

Postcondition:

returns true iff the stack is empty

Returns:

True iff there is no more room in the stack.

toString

public String toString()

Construct a string representation of the stack.

Overrides:

toString in class Object

Postcondition:

returns a string representation of stack

Returns:

A string representing the stack.