edu.princeton.cs.algorithms

Class Bag<Item>

java.lang.Object

edu.princeton.cs.algorithms.Bag<Item>

All Implemented Interfaces:

Iterable<Item>

public class Bag<Item>
extends Object
implements Iterable<Item>

The Bag class represents a bag (or multiset) of generic items. It supports insertion and iterating over the items in arbitrary order.

This implementation uses a singly-linked list with a static nested class Node. See LinkedBag for the version from the textbook that uses a non-static nested class. The add, isEmpty, and size operations take constant time. Iteration takes time proportional to the number of items.

For additional documentation, see Section 1.3 of Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.

Author:

Robert Sedgewick, Kevin Wayne

Constructor Summary

Constructors

Constructor and Description
Bag() Initializes an empty bag.

Method Summary

Modifier and Type	Method and Description
void	add(Item item) Adds the item to this bag.
boolean	isEmpty() Is this bag empty?
Iterator<Item>	iterator() Returns an iterator that iterates over the items in the bag in arbitrary order.
static void	main(String[] args) Unit tests the Bag data type.
int	size() Returns the number of items in this bag.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

Bag

public Bag()

Initializes an empty bag.

Method Detail

isEmpty

public boolean isEmpty()

Is this bag empty?

Returns:

true if this bag is empty; false otherwise

size

public int size()

Returns the number of items in this bag.

Returns:

the number of items in this bag

add

public void add(Item item)

Adds the item to this bag.

Parameters:

item - the item to add to this bag

iterator

public Iterator<Item> iterator()

Returns an iterator that iterates over the items in the bag in arbitrary order.

Specified by:

iterator in interface Iterable<Item>

Returns:

an iterator that iterates over the items in the bag in arbitrary order

main

public static void main(String[] args)

Unit tests the Bag data type.