CSci 161 Midterm Exam

Topics for the Fall 2009 midterm exam:

• ordered or unordered arrays
• insert, delete, search operations ... be able to code some of these
• Binary search of an ordered array ... where does the search begin? how does it proceed?

• constructors ... what do they do?
• fields ... what are they used for?
• methods ... what are they?
• modifiers: public, private, protected

• console output and keyboard input
• command line parameters ... be able to write code that fetches them
• InputStream and OutputStream: read and write bytes (only)
• file I/O: text files, binary files, files of objects
• higher lever tools: InputStreamReader, BufferedReader ... read a character, read a line
• higher lever tools: DataInputStream, DataOutputStream ... readInt(), readDouble(), writeInt(), writeDouble(), etc.
• higher lever tools: ObjectInputStream, ObjectOutputStream ... readObject(), writeObject()
• remote files and URLs

• what is an exception? - one answer is this: a signal that some event important to your program has occurred
• examples of exceptions: array index out of bounds, division by zero, end of file, file not found, ...
• exceptions can be handled or thrown ... what do these words mean?
• when is it necessary to handle an exception?
• what Java code is required in order to handle an exception?
• what is the alternative to handling an exception?
• what java code is necessary in a method that does not intend to handle an exception?

• push(), pop(), peek() methods and their descriptions
• efficiency of the push() and pop() methods for a stack containing N items ... answer O(1) if well implemented using an array
• the Stack interface ... be able to code it in Java
• be able to code one or more of these methods

• enqueue(), dequeue(), front() methods and their descriptions
• efficiency of the enqueue() and dequeue() methods for a queue containing N items ... answer O(1) if well implemented using an array
• the Queue interface ... be able to code it in Java
• be able to code one or more of these methods

• insert(), delete(), peek() methods
• efficiency of insert() and delete() for a queue containing N items when implemented as an unordered array ... O(1), O(N)
• efficiency of insert() and delete() for a queue containing N items when implemented as an ordered (by priority) array ... O(N), O(1)

• insertion sort ... what does a array look like after 1 pass? after 2 passes? ...
• bubble sort ... what does a array look like after 1 pass? after 2 passes? ...
• selection sort ... what does a array look like after 1 pass? after 2 passes? ...
• efficiency of these algorithms is O(N²)

• what is recursion?
• how and why does recursion work?
• 3 things to check for are ...

Old Exams: Fall 2005 (with solutions), Spring 2006 (without solutions), Fall 2007 (without solutions), Spring 2008 (with solutions) Fall 2009 (with solutions)