Answer
The argument is invalid by the converse error
Work Step by Step
p: This computer program is correct
q: It produces the correct output when run with the given test data
If this computer program is correct, then it produces the correct output when run with the test data my teacher gave me. (p → q)
This computer program produces the correct output when run with the test data my teacher gave me. (q)
∴ This computer program is correct. (p)
The argument flow is like:
p → q
q
∴ p
which follows the faulty reasoning known as the converse error.