AP CSP MCQ Review Session 3 Quiz

A student wants to determine whether a certain problem is undecidable. Which of the following will demonstrate that the problem is undecidable?

• Show that for one instance of the problem, an algorithm can be written that is always capable of providing a correct yes-or-no answer.

• Show that for one instance of the problem, no algorithm can be written that is capable of providing a correct yes-or-no answer.

• Show that for one instance of the problem, a heuristic is needed to write an algorithm that is capable of providing a correct yes-or-no answer.

• Show that for one instance of the problem, an algorithm that runs in unreasonable time can be written that is capable of providing a correct yes-or-no answer.

Consider the following procedure. PROCEDURE doSomething(num1, num2) { DISPLAY(num1) RETURN(num1) DISPLAY(num2) } Consider the following statement. DISPLAY(doSomething(10, 20)) What is displayed as a result of executing the statement above?

• A. 10 10

• B. 10 20

• C. 10 10 20

• D. 10 20 10

A student wrote the procedure above to calculate the sum of the integers from 1 to 5. The student later decides to modify the procedure to calculate the sum of the integers from 1 to max, which represents any positive integer greater than 1. Which of the following changes should be made to the procedure to meet the student’s goal?

• I only

• II only

• I and II

• I and III

A student is developing a program that allows users to look up the definitions of words that appear in a book. The student plans to perform a large number of searches through a dictionary containing words and their definitions. The student will use a procedure written by a computer scientist to quickly search the dictionary (and knows that the procedure will return a definition if one is available). The student cannot modify the search procedure written by the computer scientist but can call the procedure by supplying a word. Which of the following is a true statement about the student’s use of the computer scientist’s search procedure?

• The student is changing the search procedure’s internal abstractions.

• The student is modifying the search procedure to take a definition as an argument and return the corresponding word.

• The student is reusing the computer scientist’s procedural abstraction by knowing what the procedure does without knowing how it does it.

• The student is reusing the computer scientist’s procedural abstraction by using duplicate code each time a search needs to occur.

A student is writing a program that is intended to replace each negative value in a particular column of a spreadsheet with the value 0. Which of the following procedures is most likely to be useful in the student’s program?

• A procedure containsNegatives, which returns true if any negative values appear in the column and returns false otherwise.

• A procedure countNegatives, which returns the number of negative values that appear in the column.

• A procedure findNegative, which returns the row number of the first negative value that appears in the column or -1 if there are no negative values.

• A procedure minimum, which returns the minimum value that appears in the column.

A spinner contains 12 regions of equal size. The regions are numbered 1 to 12. Which of the following code segments can be used to simulate the results of spinning the spinner three times and assigns the sum of the values obtained by the three spins to the variable sum?

• sum ← RANDOM(1, 12) + RANDOM(1, 12) + RANDOM(1, 12)

• sum ← RANDOM(1, 36)

• sum ← 3 * RANDOM(1, 12)

• sum ← 12 * RANDOM(1, 3)

The code segment above can be used to simulate the bonus round. Which of the following is NOT a possible output of this simulation?

• The player had 1 bonus round attempts and 1 of them earned extra points.

• The player had 2 bonus round attempts and 0 of them earned extra points.

• The player had 3 bonus round attempts and 7 of them earned extra points.

• The player had 4 bonus round attempts and 3 of them earned extra points.

In which of the following scenarios is using a simulation more beneficial than performing a calculation? Select TWO answers.

• A. Determining the average grade of the students in a certain class

• B. Keeping track of the high score in a game

• C. Investigating ways to reduce the amount of trash in the ocean

• D. Studying the effect of a genetic change in a population

In which of the following scenarios would a simulation be the LEAST beneficial?

• An engineering company wants to test whether a change to a car design will negatively affect fuel efficiency.

• An insurance company wants to study the effect of cold weather patterns on health-care costs.

• A manufacturing company wants to determine whether using robots in its facility will increase productivity.

• A retail company wants to determine the most popular item that was sold on the company’s Web site last month.

A computer scientist is analyzing four different algorithms used to sort a list. The table below shows the number of steps each algorithm took to sort lists of different sizes. Based on the values in the table, which of the algorithms appear to run in reasonable time? Select TWO answers.

• Algorithm A

• Algorithm B

• Algorithm C

• Algorithm D