CS 1713 Introduction to Computer Science, Fall 2008 Project 1 Comments

• Most people did not follow the directions:
  
  The tester must output enough information so that someone reading the output can tell what tests were performed and whether they were successful.
  If you output: The product of p1 and p2 is ....,
  you should be able to tell what p1 and p2 are by reading the output.

  Each time you start the tests for one part of the assignment, print a line indicating which part is being tested.

• Most people made the problem much harder than it needed to be.
• Testing is important. Many people just tested add, subtract, and multiply with one pair of polynomials.
• You should have some tests with simple polynomials so that you can easily tell if it is not working. Don't start out with polynomials of degree 6.
• You should only need two fields, the array representing the polynomial, and the PRECISION constant. YOu do not need to save the length of the array as a field.
• The add and subtract methods should be almost identical. You can write your own private method to handle both of these.
• The constructor must make a copy of the array, or the polynomial is not immutable. When doing this, you should eliminate the unneeded 0 coefficients from the end of the array.
• Choose appropriate names for your identifiers.
  Example: i is not a good identifier name for an array.
• In the tester, use lists to initialize arrays:
  int[] a1 = {2,4,5,6,-1,0,0};
• An efficient way to evaluate a polynomial is using Cramer's rule:
  P(x) = (...((a(n)x + a(n-1))x + a(n-2))x + ... a(1))x + a(0)
• Test as many special cases as possible.
  What are the special cases for toString and add?