AP CSP Exam Review

What does it mean when we say the Internet is redundant?

• Parts of it are unnecessary

• If a path is down, packets can be routed a different way

• It has a delay between the request and the response to the request

• If there is an error, a backup system is brought online to be used

What describes the process of keeping common or similar features and functionality while removing details that are different?

• An alorithm

• Decomposition

• Simulation

• Abstraction

How are algorithms and programs related?

• They have a hierarchical relationship

• Programs implement algorithms

• Algorithms implement programs

• They can both be run on a computer

What is a benefit of collaboration when writing code?

• Collaboration allows the work to be divided among independent programmers to create.

• Collaboration makes it easier to document another person's code

• Collaboration makes it eastier to find errors

• Collaboration produces an increase in user requirements that can be met with more team members.

A photographer is manipulating a digital image and overwriting the original image. Which of the following describes a lossy transformation of the digital image?

• Creating the gray scale of an image by averaging the amounts of red, green, and blue in each pixel and assigning this new value to the corresponding pixel in the new image. The new value of each pixel represents a shade of gray, ranging from white to black.
• Creating a mirrored image by swapping the RGB values from pixels on the left side of an image with RGB values from pixels on the right side of an image.
• Swapping the Red and Green values of each pixel so that areas that were red now appear green and vice versa.
• Creating the negative of an image by creating a new RGB triplet for each pixel in which each value is calculated by subtracting the original value from 255. The negative of an image is reversed from the original; light areas appear dark, and colors are reversed.

Which of the following statements are true about lossless compression?
I - Lossless compression is used only to send files over the Internet
II - Sending a compressed version of a file ensures that the contents of the file cannot be intercepted by an unauthorized user.

• I only
• II only
• I and II
• Neither I nor II

A red triangle is pictured below in a grid of squares. It is currently facing upward, and can only move using the MoveTriangle procedure, shown below. The triangle can move onto white and gray squares, but not onto the black squares.

PROCEDURE MoveTriangle (numMoves, numTurns)
{  
 REPEAT numMoves TIMES   
 {  
 MOVE_FORWARD()  
 }  
 REPEAT numTurns TIMES  
 {    
 TURN_RIGHT()  
 }
}

Which of the following instructions will get the red triangle to the gray square?

• MoveTriangle (1, 1) MoveTriangle (1, 1) MoveTriangle (3, 1) MoveTriangle (3, 0)

• MoveTriangle (4, 1)

  MoveTriangle (4, 0)

• MoveTriangle (1, 1)

  MoveTriangle (1, 3)

  MoveTriangle (3, 1)

  MoveTriangle (3, 0)

   
• MoveTriangle (1, 1)

  MoveTriangle (1, 3)

  MoveTriangle (3, 3)

  MoveTriangle (3, 0)

Efficiency of algorithms is most often analyzed based on which of the following characteristics?

• The number of lines of computer code needed to implement the algorithm.
• The time and memory space necessary to run the algorithm.
• How easy or difficult the algorithm is to understand.
• The size of the output obtained after running the algorithm.

Which of the following statements about abstraction is true?

• Abstraction requires users to understand the low-level details of a system.
• Abstraction reduces information and detail to facilitate focus on relevant concepts.
• Abstraction increases the run-time complexity of a program.
• Abstraction compresses a program file to reduce file size.

A programmer is writing code to switch the values of two integer variables, namely a and b, using a temporary integer variable, temp. Will the pseudo-code correctly perform the required task (assume that a and b are never numerically equal)?
This is the pseudo-code that the programmer has come up with:

temp ← a  # statement 1.
b ← temp  # statement 2.
a ← b  # statement 3.

• Yes, the code correctly switches the values of 'a' and 'b'.
• No, but it will work correctly if statements 1. and 3. are switched.
• No, but it will work correctly if statements 2. and 3. are switched.
• No, but it will work correctly if statements 1. and 2. are switched.