AP Computer Science Exam with Verified Answers

AP Computer Science Exam with
Verified Answers
Which of the following is true of algorithms? - ✔✔C. Every algorithm can be constructed using
combinations of sequencing, selection, and iteration


The following algorithm is followed by a person every morning when they get up from bed to go
to school
Wake up
Brush teeth
Put on shirt
Put on pants
Put on socks
Put on shoes

Tie shoes - ✔✔A.

Sequencing


3.
Which of these algorithms will move the robot along the same path as the algorithm below?


REPEAT 2 TIMES { REPEAT 3 TIMES { MOVE_FORWARD() } ROTATE_LEFT() MOVE_FORWARD()
ROTATE_RIGHT() } - ✔✔Repeat 2 times

{
Move_forward()
Move_forward()
Move_forward()
Rotate_left()

,Move_forward()
rotate_right()
}


A town government is designing a new bus system and are deciding where to put the different
bus stops. They want to pick the collection of locations that minimizes the distance anyone
needs to walk in order to get to at least one bus stop. What term best defines the kind of
problem? - ✔✔B. An optimization problem


The algorithm below is used to find the largest element in a list of numbers.
By modifying one of the lines in the program it is possible to make the algorithm find the
SMALLEST element. Which line would need to be modified and how?
01 target <- list[1] 02 FOR EACH num IN list 03 { 04 IF(num > target) 05 { 06 target <- num 07 }
08 } 09 DISPLAY(target) - ✔✔B.

Line 04 becomes IF (num < target)



Which of the following algorithms is the same as the flowchart shown below? - ✔✔myNum <--
Random(1,10)
Repeat Until (myNum > 8)
{
Display (myNum)
myNum <-- RANDOM(1,10)
}
Display("Done")


This graph shows the efficiencies of two different algorithms that solve the same problem.
Which of the following is most efficient? - ✔✔D.

The algorithms have different efficiencies depending on the input size

, A school is creating class schedules for its students. The students submit their requested
courses and then a program will be designed to find the optimal schedule for all students.
The school has determined that finding the absolute best schedule cannot be solved in a
reasonable time. Instead they have decided to use a simpler algorithm that produces a good
but non-optimal schedule in a more reasonable amount of time.

Which principle does this decision best demonstrate? - ✔✔B.

Heuristics can be used to solve some problems for which no reasonable algorithm exists



Which of the following algorithmic efficiencies would be considered LEAST efficient? - ✔✔D.

Exponential



Which of the following best describes the existence of undecidable problems? - ✔✔D.
An undecidable problem is a problem for which no algorithm can be constructed that always
produces a correct output


A group of students writes their names and unique student ID numbers on sheets of paper. The
sheets are then randomly placed in a stack.
Their teacher is looking to see if a specific ID number is included in the stack. Which of the
following best describes whether their teacher should use a linear or a binary search? - ✔✔D.

Only the linear search will work since the data has not been sorted


A computer is performing a binary search on the sorted list of 7 numbers below. What is the
maximum number of iterations needed to find the item?

[1, 5, 20, 50, 51, 80, 99] - ✔✔B. 3


Which of the following are benefits of parallel and distributed computing?
I. Distributed computing improves the speed at which an individual computer executes a
program
II. Parallel computing scales more effectively than sequential computing