AP CSP Distance Learning Test

The code segment above is intended to swap the values of the variables first and second using a temporary variable, temp.

Which of the following can be used to replace <MISSING CODE> so that the code segment works as intended?

• second <-- first

• second <-- temp

• temp <-- first

• temp <-- second

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 binary numbers. According to ASCII character encoding, which of the following letters is represented by the 8-bit binary value: 0100 0010

• ASCII Character: A

• ASCII Character: B

• ASCII Character: D

• The table does not contain the value represented by the binary number 0100 0010

Which of the following is NOT true about TCP/IP packets?

• Packets are numbered so if they arrive out of order the message can be reassembled.

• TCP guarantees that no packets are ever dropped

• Packets can be routed on different paths from sender to receiver.

• Messages are broken into packets to improve reliability of the internet

A compression scheme for long strings of bits called run-length encoding is described as follows:

Rather than record each 0 and 1 individually, instead record "runs" of bits by storing the number of consecutive 1s and 0s that appear. Since it's binary, any run of 0s must be followed by a run of 1s (even if the run is only 1-bit long) and vice versa. Thus, you can store a list of small numbers that represents the alternating runs of 0s and 1s. There is an example pictured above.

To uncompress the data back into its original binary state, you simply reverse the process. This technique is an example of what type of compression?

• Lossless compression

• Fast Fourier Transform compression

• Lossy compression

• Tailored compression

A raw digital sound file samples a sound wave at some interval and measures the height of the wave at each point. Thus, raw sound is recorded as a list of numbers.

In very broad terms the MP3 audio compression algorithm identifies frequencies and volume levels - low and high - that are outside the range of human hearing and removes the data representing these frequencies from the original. This technique results in a smaller audio file that sounds exactly the same to the human ear. This technique is an example of what type of compression?

• Fast Fourier Transform compression

• Lossless compression

• Lossy compression

• Tailored compression

Under which of the following conditions is it most beneficial to use a heuristic approach to solve a problem?

• When the problem can be solved in a reasonable time and an approximate solution is acceptable

• When the problem can be solved in a reasonable time and an exact solution is needed

• When the problem cannot be solved in a reasonable time and an approximate solution is acceptable

• When the problem cannot be solved in a reasonable time and an exact solution is needed

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?

• 
• 
• 
• 

17. Consider the program code shown.

Which of the following best describes the result of running the program code?

• The number 0 is displayed.

• The number 6 is displayed.

• The number 10 is displayed.

• Nothing is displayed; the program results in an infinite loop.

What is a Distributed Denial of Service (DDoS) attack?

• A coordinated effort by a group to simultaneously attempt to gain entry to foreign government's servers or systems

• An effort by network engineers to focus all systems on catching a user or computer that has illegally gained access.

• An attempt to compromise a single target by flooding it with requests from multiple systems.

• An attempt to harass or extort all customers of one or more Internet Service Providers (ISPs).

Which of the following scenarios is most characteristic of a phishing attack?

• You accidentally run a piece of code that automatically spreads from one computer to another, exploiting a common vulnerability

• You get an email from the IT support desk that asks you to send a reply email with your username and password to verify your account

• You get an unwanted email trying to sell you a low quality product or service that seems "fishy."

• You accidentally install a piece of software that monitors your activity to steal personal information like your passwords, date of birth, social security number, etc.