CS 50 Homework 3 (Section 1 — Prof. Brown)

Due by class time Tuesday, February 12
  1. Programming Exercise P2.9 (page 96). Name your program Change. The output of your program should look something like this: 
       DOS> java Change
   Amount due: 4.31
   Amount received: 10.00
   Here is your change:
   5 dollars
   2 quarters
   1 dimes
   1 nickels
   4 pennies
    Files to submit: Change.java

  2. Programming Exercise P3.2 and P3.3 (page 136). Name your test program TestEmployee. Make sure that your program also tests out the raiseSalary method added in P3.3. Files to submit: Employee.java, TestEmployee.java

  3. Programming Exercise P3.4 (page 136). Name your test program TestCar. Files to submit: Car.java, TestCar.java

  4. Programming Exercise P3.7 (page 137). Name your test program TestStudent. Files to submit: Student.java, TestStudent.java

  5. Programming Exercise P3.8 (page 137). Name your test program TestProduct. Files to submit: Product.java, TestProduct.java

  6. Finish the design of the Ratio class discussed in lecture. This class should support the following mathematical operations on rational numbers: addition, subtraction, multiplication, division, and inversion (reciprocation). Also, you should be able to construct ratios from either a numerator-denominator pair, a single integer, or with no parameter at all (in which case the default value is the ratio 1/1). Use Ratio.java and TestRatio.java as your starting point for this problem. The output of TestRatio should look something like this: 
       DOS> java TestRatio
   r1 = 1.3333333333333
   r2 = 1.5
   r3 = 0.1666666666666
   1/r3 = 6.0
    Files to submit: Ratio.java, TestRatio.java

Turning in Your Homework

To turn in your homework, put the specified files into a single folder named Your Name HW 3 and drop this folder into the drop box. If you are an off-campus student, you may copy your folder to a CLEAN floppy disk (one containing no other files or folders), and hand this in at the beginning of class, instead of using the drop box.