Computer Science 261

Programming Assignment #1

Due: Monday, Sept. 16

Purpose: The purpose of this assignment is to

• Start getting comfortable with the form of a Java program
• Start getting familiar with the JCreator tools
• Make sure that the handin system works correctly
• Review some basics from CSci 161

1. Please write a program, called quad.java, which accepts three real (double) numbers from the user (call them A, B, and C for now) and which then calculates and prints the solution(s) to the quadratic equation A*x^2 + B*x + C = 0 according to the following rules:
   • If A = B = 0 then there is no solution, else
   • If A = 0 then the solution is x = -C/B
   • Otherwise, calculate D = B^2 - 4*A*C
     • If D < 0 there are no (real) solutions
     • If D = 0 the solution is x = -B/(2*A)
     • Else there are two solutions: x = (-B+sqrt(D))/(2*A) and x = (-B-sqrt(D))/(2*A)

• As a part of the quad.java program, include in your comments a test set adequate to reasonably test correct input (don't worry about testing errors at this point). Give brief justifications for each test.

1. Write a second program, called Fibonacci.java, which accepts an integer N and then calculates the Nth Fibonacci number three ways
   • By using a loop without any functions or arrays
   • By using an array
   • By using a recursive function.

We will discuss the details of submitting programs Monday.

• You will need to set up a workspace on your filestore on Alexandria (drive H:)
  • File -> New -> workspace
• Call it anything you want to
• Create an empty project (again File -> New -> project). Be sure to select an empty project (we will look at some of the other options later)
• Create a Java file (File -> New etc.)
• If not automatically added to your project, go to Project -> add files and add the file to the project.
• One trick is to keep the same project and workspace, and to change the files around. To remove a file from the project, make sure that the window is closed (remember that we discovered this today in class), select the project, and then select delete from the edit menu.

Any questions/problems? Please ask!