AP CSP Exam Review: Big Idea 3

Which of the following procedures would be most useful as part of a program to determine whether a word appears in two different text files?

• A procedure getWords, which takes a positive integer n and a text file as input and returns the first n words in the text file.

• A procedure textMatch, which takes two text files as input and returns true if the two text files are identical.

• A procedure isFound, which takes a word and a text file as input and returns true if the word appears in the text file

• A procedure sameSize, which takes two text files as input and returns true if the two text files contain the same number of words.

A web developer is creating an online lottery scratch card. The attached incomplete code segment decides whether the player wins a prize. The code should only give the player a 3% chance of winning a prize.

Which of these can replace <MISSING CONDITION> so that the code works as intended?

(Select two answers)

• RANDOM(1, 100) > 97

• RANDOM(1, 100) >= 97

• RANDOM(1, 100) <= 3

• RANDOM(1, 100) < 3

A computer science student completes a program and asks a classmate for feedback. The classmate suggests rewriting some of the code to include more procedural abstraction.

Which of the following is NOT a benefit of procedural abstraction?

• Making the code run faster

• Making the code more readable

• Providing more opportunities for code reuse

• Reducing the amount of duplicated code

A high school provides email addresses to freshman students. The email system typically assigns an email address in the format "[e-mail]". However, if a student has the same name as a previous student, the system assigns them a different format.

In order to figure out whether an email address is already assigned, the system does a binary search through its list of existing email addresses.

Which of these statements is true?

• The code for the binary search algorithm must be written in binary to achieve optimum efficiency

• The list of email addresses don’t need to be sorted for binary search to work, but that would improve the efficiency of the algorithm

• In the worst-case scenario that the email address is not in the list, binary search will need to look at every item in the list

• The list of email addresses must be sorted for binary search to work

Consider the attached procedures.

What is displayed as a result of the procedure call

proc2("birthday", "to you")?

• birthday happy to you

• to you happy birthday

• to you birthday happy

• birthday happy birthday

A game developer is working on a soccer video game. The attached incomplete code segment is run when a player attempts a goal from outside the 6-yard box. At that distance, the code should give the player a 30% chance of making the goal.

Which of these can replace <MISSING CONDITION> so that the code works as intended?

(Select two answers)

• RANDOM(1, 10) <= 3

• RANDOM(1, 100) = 30

• RANDOM(1, 100) <= 30

• RANDOM(1, 10) < 3

A city government would like to make their streets more bike-friendly with features such as protected bike lanes. However, government officials are concerned about the effect on traffic flow. They hire a software consultant agency to develop a simulation of the traffic after the proposed changes.

What are the most likely benefits of creating a computer simulation of the proposal?

(Select two answers)

• Once it is developed, the simulation can run at a faster speed than a real-life experiment.

• The simulation can try the addition of even more bike lanes without incurring significant extra cost for each lane added.

• As long as the software developers are not biased, the simulation will not include any bias for or against cyclists.

• Since they are developing the simulation on a computer, it should be able to represent the proposed changes with 100% accuracy.

Which of the following statements about the ability of computers is most accurate?

• There are some problems that personal computers can’t solve, but supercomputers can solve those problems when given enough time to spend on them.

• There are some problems that current computers can’t solve, but we hypothesize that more powerful computers in the near future will be able to solve them.

• Computers can solve every problem, and do so in a reasonable amount of time.

• There are some problems a computer can’t solve, no matter how much time they have.

The United States Postal Service (USPS) delivers nearly 200 million pieces of mail every day. Their website and internal operations are powered by many algorithms.

Which algorithm's runtime is most likely to be improved by the use of a heuristic?

• Calculating the cost of a package based on weight and distance to destination.

• Identifying the top-performing delivery carrier in a region, based on the carrier’s performance scores.

• Calculating an efficient route for a delivery carrier through a city, considering factors like parking space and mail volume

• Sorting packages according to the expected delivery date, from most urgent to least urgent

A company is developing a tool to detect "unreachable code": code in a program that will never be executed because no paths ever lead to that line of code. They want to release the tool with the promise that it will "find and delete 100% of the unreachable code in your codebase!"

Unfortunately, one of the programmers does some research and realizes that determining whether a line of code is unreachable is an undecidable problem.

What are the consequences of the problem being undecidable?

• The programmers may be able to come up with an algorithm to find 100% of the unreachable code, but nobody has come up with the algorithm yet, so they will need more development time.

• The programmers can come up with an algorithm that correctly determines unreachable code most of the time, but it will not correctly identify unreachable code in all cases.

• The programmers can come up with an algorithm that will find 100% of the unreachable code, but it would take an unreasonable amount of time to run.

• The tool will not be able to correctly identify any cases of unreachable code.