If you did not finish the reading assignment for the first homework assignment, finish it for this assignment. (It was [Gray], Chapters 0, 1, and Chapter 2 up through 2.2 only.) and [Bloch], items 1-5, 7-9, 13, and 31. The new reading for this assignment is [Bloch], items 17, 23-25, 27, and 39.

Submit answers to the following problems, in a nicely typeset pdf file:

1. Write a Java interface for (single-variable) polynomials whose coefficients are of type double and whose exponents are of type int and non-negative. Include methods to
   • Return the degree of the polynomial
   • Return the coefficient for a given exponent
   • Evaluate the polynomial at a given value of x
   • Add two polynomials, returning their sum
   • Subtract two polynomials, returning their difference
   • Return the derivative of a polynmial
2. Write an array-based implementation of the polynomial interface from the previous problem. Polynomials should be represented in an array of doubles, indexed by exponent.
3. Give a UML diagram for the interface and class specified in the previous two problems.
4. Write a comprehensive unit test for your array-based polynomial class.
5. Write a class for rational numbers. Include methods to add, subtract, multiply and divide. Override equals, hashCode, and toString.
6. Give a UML diagram for the rational numbers class.
7. Write a comprehensive unit test for the rational numbers class.

You will be creating a document that contains numbered solutions to the problems, using LaTeX, OpenOffice, Word, or other document preparation system. If a particular problem asks for source code, you may embed the source in place in the document, or give the answer as "See <filename>" and place the source code at the end of the document. Compose the pdf with the solutions to each problem, numbered, and in order. You must submit a hard copy of the pdf and the source code in one packet of stapled together 8.5" × 11" sheets of paper. You must also make available source code in electronic form, either by emailing me a zip file containing the sources, or by providing me readonly access to a cvs or svn repository, where I can check out code by date.

Your sources should be organized as follows:

homework
  cmsi281
    src
      main
        docs
          hw2.tex (or .odt or .doc or ...)
          <diagram source files>, if any
          <images>, if any
        java
          edu
            lmu
              cs
                math
                  Polynomial.java (an interface)
                  ArrayPolynomial.java (implements Polynomial)
                  Rational.java (a class)
      test
        java
          edu
            lmu
              cs
                math
                  ArrayPolynomialTest.java  (JUnit test case)
                  RationalTest.java (JUnit test case)

• Submissions that are not exactly in the form above will be downgraded heavily. The directory structure must be exactly as shown above, and all files must be named exactly as shown above, etc.
• Code that does not compile will get a zero.