APCSP Algorithms and Programming 2

Question 1

Which of the following best describes an undecidable problem in computer science?

Accepted Answer

A problem for which no algorithm can always produce a correct yes/no answer

Answer

An undecidable problem is one for which no algorithm can be written that will always correctly determine a yes or no answer for all possible inputs.

Question 2

A programmer writes a procedure that calls itself. What is this technique called?

Accepted Answer

Recursion

Answer

Recursion is a programming technique where a procedure calls itself to solve smaller instances of the same problem.

Question 3

What is the result of evaluating the Boolean expression: NOT (TRUE AND FALSE)?

Accepted Answer

TRUE

Answer

TRUE AND FALSE evaluates to FALSE, and NOT FALSE evaluates to TRUE.

Question 4

A list contains [3, 7, 1, 9, 4]. After one pass of a selection sort (finding and placing the minimum), what does the list look like?

Accepted Answer

[1, 7, 3, 9, 4]

Answer

Selection sort finds the minimum (1) and swaps it with the first element (3), yielding [1, 7, 3, 9, 4].

Question 5

Which of the following is an example of a heuristic approach to solving a problem?

Accepted Answer

Using a 'good enough' approximation strategy when an exact solution is impractical

Answer

A heuristic is a problem-solving approach that finds an approximate solution quickly when finding the exact solution would be too time-consuming.

(APCSP) AP Computer Science Principles Practice Test