The following content is provided under a Creative
Commons license.
Your support will help MIT OpenCourseWare
continue to offer high quality educational resources for free.
To make a donation, or view additional materials
from hundreds of MIT courses, visit MIT OpenCourseWare
at ocw.mit.edu.
ANA BELL: Let's look at this exercise.
So we have this function is even, same one as before,
except now I'm giving you this implementation.
If n is positive and n divided by 2's remainder is 0,
return true.
So if n is even and positive return true.
The next one, if n is negative and divisible by 2 return true.
OK, so far.
And otherwise return false.
Question being, with that implementation
is this test set n is 4, n is minus 4 path complete?
And the answer is, yes.
Because 4 is a positive number and divisible by 2.
Minus 4 is a negative number and divisible by 2.
And 5 would hit upon the else.
So the answer is actually yes for that first question.
Perfect.
Second question, with that implementation,
which value for n is incorrectly labeled by that program?
Well, n is very large still works, and is very small
still works.
And remember, I said you have to test boundary conditions.
In this case, boundary conditions for this program
being when n is equal to zero.
So I think the orange is n is equal to 0.
Perfect.