These are the instructions given to the graders when they graded Quiz 2.

If the program does not compile and/or not run, you need to look at the code, and manually trace it to find out why.  Don't take points off if it doesn't compile, though -- the system does that automatically. 

Sample Output

There was one test case run, with the input being 20.  The output should be a list of the numbers from 3 to 20, with each number having "prime" or "composite" after it, as appropriate.

Prime number listing

Enter max number: 20
2 prime
3 prime
4 composite
5 prime
6 composite
7 prime
8 composite
9 composite
10 composite
11 prime
12 composite
13 prime
14 composite
15 composite
16 composite
17 prime
18 composite
19 prime
20 composite

Programming style

• 10 points: Program header (includes name, e-mail ID, and purpose)
  If a major structure is missing (such as the main() method), then points are taken off here
  • -5 if 1 is missing
  • -10 if 2 or more are missing
  • -10 if the class line is wrong (or the main() method prototype is wrong)
     
• 10 points: Good commenting and use of whitespace
  Each "block" of code (a "block" is one or two lines of code) should be separated by a blank line, and have a line of commenting above it.
  • -5 for excessively long lines in code
  • -5 for excessive whitespace (more than 2-3 lines)
  • -2 for each misleading comments
  • -5 for bad indentation
     

Input and output

• 10 points: Input: Proper Scanner creation; proper usage for obtaining input
  ...
  • -10 if they obtain the input in the wrong order, but grade the rest of the quiz as if the input was provided in the order they desired
  • -3 if they declare multiple Scanner objects (program will encounter a run-time exception if this occurs)
  • -10 if they use BufferedReader and InputStream instead of Scanner
  • -10 if they use Scanner.create() rather than new Scanner()
  • -5 if they use nextLine() instead of next()
     
• 10 points: Output: prints an appropriate legend
  They need to have a valid prompt, and read it via a Scanner method . 
  • -5 for no legend
     

Program steps

If they commented something out and it would have worked, they get 2/3 points for that part (round normally -- 0.5 and above rounds up).  If they commented something out and it had bugs in it, they get 1/3 points for that part (round normally again).  And if they got it more-or-less correct, but had some errors, then half credit for that section.

• 20 points: Proper nested loop structure
  They should have two nested loops -- one to run from 2 to n, and one to compute all the divisors.
  • Outer loop
    • -10 if missing
    • -2 if they print 1
    • -2 if they print 0 (in addition to the penalty on the previous line)
    • -2 if they do not print that 20 is composite
    • -2 if they do not print that 2 is prime
    • -5 if the loop bounds are incorrect
  • Inner loop
    • -10 if missing
    • -5 if the loop bounds are incorrect
       
• 20 points: Proper testing (and printing) of composite numbers
  Testing - 15 pts; Printing - 5 pts
  • -5 if they were close to the right answer
  • -10 if they had the right idea or at least made a strong effort
  • -15 if they had no idea how to test (or did not test at all)
  • -5 if printing is bad (e.g. incorrect output, but correct logic); do not take these points off if the printing could have been correct better logic
     
• 20 points: Proper testing (and printing) of prime numbers
  This part is a bit harder than composite numbers.  Testing - 15 pts; Printing - 5 pts
  • -5 if they were close to the right answer
  • -10 if they had the right idea or at least made a strong effort
  • -15 if they had no idea how to test (or did not test at all)
  • -5 if printing is bad (e.g. incorrect output, but correct logic); do not take these points off if the printing could have been correct better logic