structure
Class SinglyLinkedList

java.lang.Object
  structure.AbstractStructure
      structure.AbstractList
          structure.SinglyLinkedList

All Implemented Interfaces:

List, Structure

public class SinglyLinkedList
extends AbstractList

Singly linked lists have elements connected by a single reference. They are space-efficient, but tail-related operations may be more costly than with doubly linked lists.

See Also:

DoublyLinkedList

Field Summary

protected int	count The number of elements in list.
protected Node	head The head of the list.

Constructor Summary

SinglyLinkedList()
Construct an empty list.

Method Summary

void	add(int i, java.lang.Object o) Insert value at location.
void	add(java.lang.Object value) Add an object to tail of list.
void	addFirst(java.lang.Object value) Add a value to head of list.
void	addLast(java.lang.Object value) Add a value to tail of list.
void	clear() Remove all values from list.
boolean	contains(java.lang.Object value) Check to see if a value is in list.
java.lang.Object	get(int i) Get value at location i.
java.lang.Object	getFirst() Fetch first element of list.
java.lang.Object	getLast() Fetch last element of list.
int	indexOf(java.lang.Object value) Determine first location of a value in list.
java.util.Iterator	iterator() Returns an iterator traversing list from head to tail.
int	lastIndexOf(java.lang.Object value) Determine last location of a value in list.
java.lang.Object	remove(int i) Remove and return value at location i.
java.lang.Object	remove(java.lang.Object value) Remove a value from list.
java.lang.Object	removeFirst() Remove a value from first element of list.
java.lang.Object	removeLast() Remove last value from list.
java.lang.Object	set(int i, java.lang.Object o) Set value stored at location i to object o, returning old value.
int	size() Determine number of elements in list.
java.lang.String	toString() Construct a string representing list.

Methods inherited from class structure.AbstractList

get, isEmpty, remove

Methods inherited from class structure.AbstractStructure

elements, hashCode, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface structure.Structure

elements, values

Field Detail

count

protected int count

The number of elements in list.

head

protected Node head

The head of the list. A reference to a singly linked list element.

Constructor Detail

SinglyLinkedList

public SinglyLinkedList()

Construct an empty list.

Postcondition:

generates an empty list

Method Detail

add

public void add(java.lang.Object value)

Add an object to tail of list.

Specified by:

add in interface List

Specified by:

add in interface Structure

Overrides:

add in class AbstractList

Parameters:

value - The value to be added to tail of list.

See Also:

#addToHead

Postcondition:

value is added to end of list (see addLast)

addFirst

public void addFirst(java.lang.Object value)

Add a value to head of list.

Specified by:

addFirst in interface List

Overrides:

addFirst in class AbstractList

Parameters:

value - The value to be added to head of list.

Postcondition:

value is added to beginning of list

removeFirst

public java.lang.Object removeFirst()

Remove a value from first element of list.

Specified by:

removeFirst in interface List

Overrides:

removeFirst in class AbstractList

Returns:

The value actually removed.

Precondition:

list is not empty

Postcondition:

removes and returns value from beginning of list

addLast

public void addLast(java.lang.Object value)

Add a value to tail of list.

Specified by:

addLast in interface List

Overrides:

addLast in class AbstractList

Parameters:

value - The value to be added to tail of list.

Postcondition:

adds value to end of list

removeLast

public java.lang.Object removeLast()

Remove last value from list.

Specified by:

removeLast in interface List

Overrides:

removeLast in class AbstractList

Returns:

The value actually removed.

Precondition:

list is not empty

Postcondition:

removes last value from list

getFirst

public java.lang.Object getFirst()

Fetch first element of list.

Specified by:

getFirst in interface List

Overrides:

getFirst in class AbstractList

Returns:

A reference to first element of list.

Precondition:

list is not empty

Postcondition:

returns first value in list

getLast

public java.lang.Object getLast()

Fetch last element of list.

Specified by:

getLast in interface List

Overrides:

getLast in class AbstractList

Returns:

A reference to last element of list.

Precondition:

list is not empty

Postcondition:

returns last value in list

contains

public boolean contains(java.lang.Object value)

Check to see if a value is in list.

Specified by:

contains in interface List

Specified by:

contains in interface Structure

Overrides:

contains in class AbstractList

Parameters:

value - The value sought.

Returns:

True if value is within list.

Precondition:

value is not null

Postcondition:

returns true iff value is found in list

remove

public java.lang.Object remove(java.lang.Object value)

Remove a value from list. At most one value will be removed.

Parameters:

value - The value to be removed.

Returns:

The actual value removed.

Precondition:

value is not null

Postcondition:

removes first element with matching value, if any

size

public int size()

Determine number of elements in list.

Returns:

The number of elements in list.

Postcondition:

returns number of elements in list

clear

public void clear()

Remove all values from list.

Postcondition:

removes all elements from list

get

public java.lang.Object get(int i)

Get value at location i.

Parameters:

i - position of value to be retrieved.

Returns:

value retrieved from location i (returns null if i invalid)

Precondition:

0 <= i < size()

Postcondition:

returns object found at that location

set

public java.lang.Object set(int i,
                            java.lang.Object o)

Set value stored at location i to object o, returning old value.

Parameters:

i - location of entry to be changed.

o - new value

Returns:

former value of ith entry of list.

Precondition:

0 <= i < size()

Postcondition:

sets ith entry of list to value o, returns old value

add

public void add(int i,
                java.lang.Object o)

Insert value at location.

Parameters:

i - index of this new value

o - value to be stored

Precondition:

0 <= i <= size()

Postcondition:

adds ith entry of list to value o

remove

public java.lang.Object remove(int i)

Remove and return value at location i.

Parameters:

i - position of value to be retrieved.

Returns:

value retrieved from location i (returns null if i invalid)

Precondition:

0 <= i < size()

Postcondition:

removes and returns object found at that location

indexOf

public int indexOf(java.lang.Object value)

Determine first location of a value in list.

Parameters:

value - value sought

Returns:

index (0 is first element) of value, or -1

Precondition:

value is not null

Postcondition:

returns the (0-origin) index of value, or -1 if value is not found

lastIndexOf

public int lastIndexOf(java.lang.Object value)

Determine last location of a value in list.

Parameters:

value - value sought.

Returns:

index (0 is first element) of value, or -1

Precondition:

value is not null

Postcondition:

returns the (0-origin) index of value, or -1 if value is not found

iterator

public java.util.Iterator iterator()

Returns an iterator traversing list from head to tail.

Returns:

An iterator to traverse list.

See Also:

AbstractIterator, Iterator, Enumeration, Structure.elements()

Postcondition:

returns enumeration allowing traversal of list

toString

public java.lang.String toString()

Construct a string representing list.

Overrides:

toString in class java.lang.Object

Returns:

A string representing list.

Postcondition:

returns a string representing list