DogWalker is #1 from the from the 2025 AP Computer Science A Free Response problems.

https://apcentral.collegeboard.org/media/pdf/ap25-frq-computer-science-a.pdf

Part (a) walkDogs method

public int walkDogs(int hour)
{
    int dogsToWalk = Math.min(maxDogs, company.numAvailableDogs(hour));
    company.updateDogs(hour, dogsToWalk);
    return dogsToWalk;
}

Part (b) dogWalkShift method

public int dogWalkShift(int startHour, int endHour)
{
    int earnings = 0;

    for(int hour = startHour; hour <= endHour; hour++)
    {
        int dogsWalked = walkDogs(hour);
        earnings += dogsWalked * 5;

        if((hour >= 9 && hour <= 17) || dogsWalked == maxDogs)
            earnings += 3;
    }

    return earnings;
}

Java files with test code

DogWalkCompany.java
DogWalker.java
OneTest.java

See Running JUnit 5 tests.

2025 AP CS Exam Free Response Solutions

• SignedText Free Response Solution
• Round Free Response Solution
• SumOrSameGame Free Response Solution

Help & comments

Get help from AP CS Tutor Brandon Horn

See an error? Question? Please comment below.

Comment on DogWalker

2025-05-10 comment

Anonymous

Do you think I will get points off if for part A i used wrong syntax instead of company.updateDogs(hour, dogs) i just used updateDogs(hour, dogs)

Response

Calling a method with a correct implicit parameter is a key part of Question 1. My best guess is that this will be an explicit point in the scoring guidelines, possibly combined with calling company.numAvailableDogs(hour).

The scoring guidelines are typically released over the summer.