AP CSP Midterm Review

What kind of data does a float variable contain?

• Whole Numbers
• words and letters
• Decimal numbers
• true or false

What type of variable is "help"?

• Integer
• Float
• String
• List

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 chat Website allows users to post messages to the site. 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 and the city from which the message was posted.
Which of the following questions can NOT be answered using only the data and metadata collected?

• What topics are most frequently posted about in a particular city?
• When is a particular city most active on the site?
• Which users post messages most frequently?
• What topics are most frequently posted about during a particular time period?

ASCII is a character-encoding scheme that uses 7 bits to represent each character. The decimal (base 10) values 65 through 90 represent the capital letters A through Z, as shown in the table below. What ASCII character is represented by the binary (base 2) number 1010001?

• S
• R
• Q
• P

Consider the following numbers Binary 1001001Decimal 70Hexadecimal 4E Which of the following lists the numbers in order from least to greatest?

• Binary 1001001, Decimal 70, Hexadecimal 4E
• Decimal 70, Binary 1001001, Hexadecimal 4E
• Binary 1001001, Hexadecimal 4E, Decimal 70
• Decimal 70, Hexadecimal 4E, Binary 1001001

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.

A student purchases a single-user license of an online textbook and wants to share the textbook with their classmates. Under what conditions is it acceptable for the student to share this textbook?

• If the student shares only three chapters of the textbook with their classmates
• If the textbook is only shared with people in the student’s class
• If the textbook is only shared with one other classmate
• If the student gets permission from the textbook’s copyright owner