AP CSP Review

1. A video-streaming Web site uses 32-bit integers to count the number of times each video has been played. In anticipation of some videos being played more times than can be represented with 32 bits, the Web site is planning to change to 64-bit integers for the counter. Which of the following best describes the result of using 64-bit integers instead of 32-bit integers?

• (A) 2 times as many values can be represented.

• (B) 32 times as many values can be represented.

• (C) 2³² times as many values can be represented.

• (D) 3²² times as many values can be represented.

2. A programmer completes the user manual for a video game she has developed and realizes she has reversed the roles of goats and sheep throughout the text. Consider the programmer’s goal of changing all occurrences of “goats” to “sheep” and all occurrences of “sheep” to “goats.” The programmer will use the fact that the word “foxes” does not appear anywhere in the original text.

Which of the following algorithms can be used to accomplish the programmer’s goal?

• (A) First, change all occurrences of “goats” to “sheep.”

  Then, change all occurrences of “sheep” to “goats.”

• (B) First, change all occurrences of “goats” to “sheep.”

  Then, change all occurrences of “sheep” to “goats.” Last, change all occurrences of “foxes” to “sheep.”

• (C) First, change all occurrences of “goats” to “foxes.”

  Then, change all occurrences of “sheep” to “goats.” Last, change all occurrences of “foxes” to “sheep.”

• (D) First, change all occurrences of “goats” to “foxes.”

  Then, change all occurrences of “foxes” to “sheep.” Last, change all occurrences of “sheep” to “goats.”

3. ASCII is a character-encoding scheme that uses a numeric value to represent each character.

For example, the uppercase letter “G” is represented by the decimal (base 10) value 71. A partial list of characters and their corresponding ASCII values are shown in the table above.

ASCII characters can also be represented by hexadecimal numbers. According to ASCII character encoding, which of the following letters is represented by the hexadecimal (base 16) number 56?

• (A) A

• (B) L

• (C) V

• (D) Y

4. The figure above shows a circuit composed of two logic gates. The output of the circuit is true.

Which of the following is a true statement about input A?

• (A) Input A must be true.

• (B) Input A must be false.

• (C) Input A can be either true or false.

• (D) There is no possible value of input A that will cause the circuit to have the output true.

5. The following question uses a robot in a grid of squares. The robot is represented as a triangle,

which is initially in the bottom left square of the grid and facing right.

Which of the following shows the location of the robot after running the code segment?

• 
• 
• 
• 

6. Which of the following statements describes a limitation of using a computer simulation to

model a real-world object or system?

• (A) Computer simulations can only be built after the real-world object or system has been

  created.

• (B) Computer simulations only run on very powerful computers that are not available to the

  general public.

• (C) Computer simulations usually make some simplifying assumptions about the real-world

  object or system being modeled.

• (D) It is difficult to change input parameters or conditions when using computer simulations.

7. A certain social media Web site allows users to post messages and to comment on other messages that have been posted. When a user posts a message, the message itself is considered data. In addition to the data, the site stores the following metadata.

▪ The time the message was posted

▪ The name of the user who posted the message

▪ The names of any users who comment on the message and the times the comments were made

For which of the following goals would it be more useful to analyze the data instead of the metadata?

• (A) To determine the users who post messages most frequently

• (B) To determine the time of day that the site is most active

• (C) To determine the topics that many users are posting about

• (D) To determine which posts from a particular user have received the greatest number of comments

8. The code segment below is intended to move a robot in a grid to a gray square. The program segment uses the procedure GoalReached, which evaluates to true if the robot is in the gray square and evaluates to false otherwise. The robot in each grid is represented as a triangle and is initially facing left. The robot can move into a white or gray square but cannot move into a black region.

REPEAT UNTIL (GoalReached ()) {

IF (CAN_MOVE (forward))

{

MOVE_FORWARD ()

}

IF (CAN_MOVE (right))

{

ROTATE_RIGHT ()

}

IF (CAN_MOVE (left))

{

ROTATE_LEFT ()

}

}

For which of the grids does the code segment NOT correctly move the robot to the gray square?

• 
• 
• 
• 

9. The table shows the time a computer system takes to complete a specified task on the customer data of different-sized companies.

Based on the information in the table, which of the following tasks is likely to take the longest amount of time when scaled up for a very large company of approximately 100,000 customers?

• (A) Backing up data

• (B) Deleting entries from data

• (C) Searching through data

• (D) Sorting data

10. Consider the code segment above.

If the variables onTime and absent both have the value false, what is displayed as a result of running the code segment?

• (A) Is anyone there?

• (B) Better late than never.

• (C) Hello. Is anyone there?

• (D) Hello. Better late than never.