Information About the First Test

The first test will be given in class on Wednesday, February 24. The test will cover everything that we have done from the beginning of the term through class on Friday, February 19. This includes exceptions and the try..catch..finally statement; the analysis of algorithms; recursion; linked lists; the concept of abstract data types; stacks and queues; binary trees, binary sort trees, and expression trees. The reading for this material is Sections 8.3, 8.6, 9.1, 9.2, 9.3, and 9.4. We have talked about a few things that are not in the textbook, notably Merge Sort and doubly-linked lists.

You can expect a variety of questions on the test. There will be some definitions and essay-type questions. There will be one or two questions that ask you to analyze the run time of some code. Some questions will ask you to write code segments or methods or possibly even complete classes. There might also be some questions that ask you to read some code and figure out what it does.

Here are some terms and ideas that you should be familiar with:

exceptions how exception handling compares to other ways of dealing with errors handling exceptions: the try..catch statement the finally clause in a try statement, and why it might be used questions of efficiency of a program run-time analysis of algorithms worst-case analysis and average case analysis log_{2}(n) and how it arises in analysis of some algorithms "Big Theta" and "Big Oh" notation ( Θ(f(n)) and O(f(n)) ) comparing Θ(n) to Θ(log(n)), or Θ(n^{2}) to Θ(n*log(n)) disregarding "constant multiples" and "lower order terms" Linear Search and Binary Search Selection Sort and Insertion Sort have run time Θ(n^{2}) Merge Sort (including how to do it by hand) Merge Sort has run time Θ(n*log(n)) Exponential run time, such as Θ(2^{n}) a program with exponential run time is infeasible except for very small inputs recursion recursive methods direct recursion and indirect recursion recursive definition of the factorial function base case of a recursion maze-solving and similar recursions infinite recursion, and why "marking" locations as already visited is important recursive geometric objects such as the Koch Curve and Sierpinski Triangle the QuickSort recursive algorithm the idea of QuickSortStep (but not the detailed code) the general idea of why QuickSort has average case run time Θ(n*log(n)) the worst case run time of QuickSort the recursive nature of grammar rules for Java and for English activation records and how they are used to implement subroutine calls How recursion is implemented using the stack of activation records linked data structures understanding names such as "employee.boss.name" and "node.next.next" simple linked lists the head of a list; why you always need to keep a pointer to the head traversing a linked list; using a "runner" to move down the list basic linked list processing, such as searching, or adding up items in a list the meaning of "while (runner != null)" and "runner = runner.next" adding a node to the head of a list why working at the head of a list is often a special case inserting and deleting nodes in a list using a "tail" pointer in a list; adding a node a the end of a list doubly-linked lists Abstract Data Types (ADTs) alternative implementations of ADTs relation of ADTs to interfaces and abstract classes the "Queue" ADT queue operations: enqueue, dequeue, isEmpty how to implement a queue as a linked list with tail pointer the "Stack" ADT stack operations: push, pop, isEmpty how to implement a stack as an array how to implement a stack as a linked list postfix expressions how to use a stack to evaluate a postfix expression binary trees recursive traversal of a tree inorder, preorder, and postorder traversals binary sort tree inserting items into a binary sort tree searching for an item in a binary sort tree balanced binary tree inserting/searching in a balanced binary sort tree has run time Θ(log(n)) expression trees to represent binary expressions finding the value represented by a an expression tree