Class 39: Discussion of Exam 2

Held: Monday, 10 November 2003

Summary: Today we go over some of the key issues from exam 2.

Related Pages:

• EBoard.
• Sample Code.
• Bad versions of in-tree?.
• The Exam.

Notes:

• Don't forget to register for CS next semester!

Overview:

• Problem 1: Memory.
• Problem 2: in-tree and Deep Recursion.
• Problem 3: list-of-symbols->string and List Recursion.
• Problem 5: number->digits and Numeric Recursion.
• Problem 4: Verifying Preconditions.

Notes on Exam 2

Problem 1 (memory)

• The big problem with equal? is efficiency.

Problem 2 (in-tree?)

• Should be simple
• Needs to illustrate mastery of deep recursion

Problem 3 (list-of-symbol->string)

• Need to handle different base cases
• Need to use a helper for the internal stuff

Problem 5 (number->digits)

• Intended to be a problem in numeric recursion.
• One special case.

Problem 4 (verifying preconditions)

• Husk-and-Kernel procedures should do complete checking before doing the real work.