CS 228 meeting -*- Outline -*-

* introduction to linked lists (HR 8.1)

	This chapter studies the *implementation* data structure of
		linked lists.
	We'll use it to implement the ADT List.

** overview

	one way to think of this is...
	Q: what would we have to do to implement something like Scheme?

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           HR CHAPTER 8
     LISTS AND LINKED LISTS

Topics:
    A. pointers and structs
    B. dynamic data implementation
       1. head nodes
       2. doubly linked lists
       3. circular lists
    C. Array implementation
       1. managing the free store (heap)
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** motivation
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          THE PROBLEM

Linear, homogeneous, ordered collection.

Often inserting and taking items out
of from random spots in the collection.
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	Like implementing the List ADT
	Examples: storing guest list at a hotel

	Q: What's the problem with using an array for this?
		have to shift when insert or delete.
		draw picture,
			note the inefficiency
	Q: What's the big-O complexity of using an array for each insertion?
		O(n)
		would like it to be linear!  (write that on the slide).


	What's the complexit of using the flexible arrays?
		O(n), as still have shifting going on.

** singly-linked lists
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       SINGLY-LINKED LISTS
     PICTURES AND TERMINOLOGY

Typical singly-linked list:





Inserting after first element:





Splicing out third element:






def: A *singly-linked list* consists of
a collection of ________ called ________,
each containing a ______________________,
and some data.
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	... structs called nodes
	... link (which is a pointer)