SAC EXAMPLE 6
Example of a Count Controlled Definite Loop.
(NOTE: This does not implement the OOSD paradigm; see the last extension.)

The (imperfect) SAC below...

EXTENSIONS:

1. Implement this algorithm in the language of your course.
2. The factorial of 0 is defined to be 1.  Does this algorithm above work for N=0?  If not, modify the algorithm so that is gives the correct answer.
3. The factorial of a negative number is undefined.  Add a error trap to the above SAC that, if a negative value of N is input, the algorithm will output an error message and halt.
4. Rather than halt the program if a negative number is input (as in extension 3), add an error trap that would keep prompting the user to input a positive number.
5. Add another for loop to the algorithm so that the factorial of the first 10 positive integers would be output as a list  (Hint: you might need to preview SAC EXAMPLE 7 before doing this.)
6. The factorial of fractional numbers is undefined.  Add an error trap that prevents anything other than positive integers being processed.  You may assume that the implementation language has the facilities to perform any mathematical operations you need.
7. Modify the SAC so that a while loop is used to accomplish the same task.  (HINT: three statements will be needed to replace the for construct.
8. How would the algorithms in this example be modified to represent OOSD?  (b) Would the different versions of this algorithm have different OOSD versions?