AP computer

The procedure BinarySearch (numList, target) correctly implements a binary search algorithm on the list of numbers numList. The procedure returns an index where target occurs in numList, or -1 if target does not occur in numList. Which of the following conditions must be met in order for the procedure to work as intended?

• The length of numList must be even.

• The list numList must not contain any duplicate values.

• The values in numList must be in sorted order.

• The value of target must not be equal to -1.

Which of the following scenarios best exemplifies a phishing attack?

• A user connects to a public wireless network. An unauthorized individual intercepts data transmitted on the network, looking for private information that can be used to gain access to the user’s accounts.

• A user’s e-mail account is overwhelmed with messages containing large attachments, which causes the account to exceed the maximum amount of data allowed and temporarily prevents the user from sending and receiving new messages.

• A user receives an e-mail from a sender offering technical help with the user’s computer. The e-mail prompts the user to start a help session by clicking a provided link and entering the username and password associated with the user’s computer.

• A user chooses a weak password for an online account. An unauthorized individual successfully guesses the user’s password from a list of common passwords.

An office uses an application to assign work to its staff members. The application uses a binary sequence to represent each of 100 staff members. What is the minimum number of bits needed to assign a unique bit sequence to each staff member?

• 5

• 6

• 7

• 8

Consider the following algorithms. Each algorithm operates on a list containing n elements, where n is a very large integer.

I. An algorithm that accesses each element in the list twice

II. An algorithm that accesses each element in the list n times

III. An algorithm that accesses only the first 10 elements in the list, regardless of the size of the list Which of the algorithms run in reasonable time?

• I only

• III only

• I and II only

• I, II, and III

Which of the following best describes the impact of Creative Commons?

• Creative Commons gives creators of digital content the ability to indicate how their works can be legally used and distributed, enabling broad access to digital information.

• Creative Commons gives Internet users the right to legally use and distribute any previously copyrighted work, enabling broad access to digital information.

• Create Commons provides lossless transmission of messages, enabling reliable distribution of digital information.

• Creative Commons provides private transmission of messages, enabling secure distribution of digital information.

A biologist wrote a program to simulate the population of a sample of bacteria. The program uses the following procedures.

Procedure Call Explanation

InitialPopulation () Returns the number of bacteria at the start of the

simulation

NextPopulation (currPop) Based on the current value of currPop, returns

the number of bacteria after one hour

Code for the simulation is shown below.

hours ← 0

startPop ← InitialPopulation ()

currentPop ← startPop

REPEAT UNTIL ((hours ≥ 24) OR (currentPop ≤ 0))

{

currentPop ← NextPopulation (currentPop)

hours ← hours + 1

}

DISPLAY (currentPop - startPop)

Which of the following are true statements about the simulation?

I. The simulation continues until either 24 hours pass or the population reaches 0.

II. The simulation displays the average change in population per hour over the course of the simulation.

III. The simulation displays the total population at the end of the simulation.

• I only

• II only

• III only

• I and II

A system is being developed to help pet owners locate lost pets. Which of the following best describes a system that uses crowdsourcing?

• A mobile application and collar that uses GPS technology to determine the pet’s location and transmits the location when the owner refreshes the application

• A mobile application and collar that uses wireless technology to determine whether the pet is within 100 feet of the owner’s phone and transmits a message to the owner when the pet is nearby

• A mobile application that allows users to report the location of a pet that appears to be lost and upload a photo that is made available to other users of the application

• A mobile application that transmits a message to all users any time a lost pet is returned to its owner

Assume that the list originalList contains integer values and that the list newList is initially empty. The following code segment is intended to copy all even numbers from originalList to newList so that the numbers in newList appear in the same relative order as in originalList. The code segment may or may not work as intended.

Line 1: FOR EACH number IN originalList

Line 2: {

Line 3: IF (number MOD 2 = 0)

Line 4: {

Line 5: INSERT (newList, 1, number)

Line 6: }

Line 7: }

Which of the following changes, if any, can be made so that the code segment works as intended?

• Changing line 1 to FOR EACH number IN newList

• Changing line 3 to IF (number MOD 2 = 1)

• Changing line 5 to APPEND (newList, number)

• No change is needed; the code segment is correct as is.

The following algorithm is intended to determine the average height, in centimeters, of a group of people in a room. Each person has a card, a pencil, and an eraser. Step 2 of the algorithm is missing.

Step 1: All people stand up.

Step 2: (missing step)

Step 3: Each standing person finds another standing person and they form a pair. If a person cannot find an unpaired standing person, that person remains standing and waits

until the next opportunity to form pairs.

Step 4: In each pair, one person hands their card to the other person and sits down.

Step 5: At this point, the standing person in each pair is holding two cards. The standing

person in each pair replaces the top number on their card with the sum of the top

numbers on the two cards and replaces the bottom number on their card with the

sum of the bottom numbers on the two cards. The sitting partner’s card is discarded.

Step 6: Repeat steps 3–5 until there is only one person standing.

Step 7: The last person standing divides the top number by the bottom number to determine the average height.

Which of the following can be used as step 2 so that the algorithm works as intended?

• Step 2: Each person writes their height, in centimeters, at the top of the card and writes the number 1 at the bottom of the card.

• Step 2: Each person writes their height, in centimeters, at the top of the card and writes the number 2 at the bottom of the card.

• Step 2: Each person writes the number 1 at the top of the card and writes their height, in centimeters, at the bottom of the card.

• Step 2: Each person writes the number 2 at the top of the card and writes their height, in centimeters, at the bottom of the card.

An online game collects data about each player’s performance in the game. A program is used to analyze the data to make predictions about how players will perform in a new version of the game.

The procedure GetPrediction (idNum) returns a predicted score for the player with ID number idNum. Assume that all predicted scores are positive. The GetPrediction procedure takes approximately 1 minute to return a result. All other operations happen nearly instantaneously.

Two versions of the program are shown below.

Version I

topScore ← 0

idList ← [1298702, 1356846, 8848491, 8675309]

FOR EACH id IN idList

{

score ← GetPrediction (id)

IF (score > topScore)

{

topScore ← score

}

}

DISPLAY (topScore)

Version II

idList ← [1298702, 1356846, 8848491, 8675309]

topID ← idList[1]

FOR EACH id IN idList

{

IF (GetPrediction (id) > GetPrediction (topID))

{

topID ← id

}

}

DISPLAY (GetPrediction (topID))

Which of the following best compares the execution times of the two versions of the program?

• Version I requires approximately 1 more minute to execute than version II.

• Version I requires approximately 5 more minutes to execute than version II.

• Version II requires approximately 1 more minute to execute than version I.

• Version II requires approximately 5 more minutes to execute than version I.