CSC161 2010F, Class 53: Linked Stacks and Queues

Overview:
* Exam 3 questions.
* Review.
* Implementing Linked Stacks.
* Implementing Linked Queues.

Admin:
* Happy CS Education Week.
* Food for week 14.
* EC for Tuesday's Women Computers movie.
* EC for Thursday's CS Extra
* Reading for Tuesday: Walker on Bash Scripts (link online).

Exam 3

* Can we use struct node instead of struct string_node and struct list 
  instead of struct string_list?
  * Yes.
* When you declare a new array of strings using the two bracket thingy.
  char strings[n][m];
  * n is number of strings.
  * m is size of string.
  * How do you allocate it?
    * The declaration does the allocation.
  * How do your refer to the 4th string?
    strings[4]
  * Cool?
    14 degrees F
* When we're referencing the fields of structures, is it not enough
  to link?
  * The compiler needs to see the declaration of the structure in order
    to figure out how to use it.
    * The declaration needs to be in the same file or in an included
      header file.
* How do I debug the problems with the macro?
  * cc -E is really helpful
* Can you cancel the loop problem?
  * Yes.
* Can it be extra credit?
  * Yes.
* How do I deal with the immutability of strings?
  * Don't put immutable strings in the list!
    list.add("Hello") is immutable
    list.add(strdup("Hello")) is mutable

Review: On Wednesday IN CLASS, we were ... yeah
* Stacks and queues and other linear collections
* Implemented using ARRAYS

But we can also implement them using linked nodes
* Easier to manage implementation
* Linked nodes are dynamic: We can keep growing the stack and queue

But how?
* Stack: Add new things to the head and remove from the head
* Queue: Add new things to the tail and remove from the head