Author Archives: Stacey Armstrong

2017 AP Computer Science A Free Response Solutions

For the 2017 AP Computer Science A exam, I have posted review slides and a student java project.

This project will allow students to punch in their code and see if works.

There are review slides for the AP Computer Science A exam for years 2006, 2008, 2010, 2011, 2012, 2013, 2014, 2015, and 2016.  There are student java projects in place now for many of the AP Computer Science Free Response sections.

Have a great summer and check out my workshop offerings if you are free this summer.

I also do local workshops for schools and school districts.  If you need specialized local training, email me and we can discuss specifics.

Good luck on the 2017 AP Computer Science Exams!

Good luck to all on the 2017 AP Computer Science exams!

Here are my predictions for this year’s 4 AP CS A Free Response Questions.  DISCLAIMER :: I have no idea what the questions will be, but I have fun each year trying to guess the topics before the exam.   I have gotten pretty good at predicting the free response topics as I do spend considerable time working with the released free response questions.

1.  ArrayList of Classes / References –  You gots to know how to write code to manipulate an ArrayList<NeverSeenThisClassBefore> as it is on the exam every single year going all of the way back to 2006.  This question type involves lots of drilling down to get to the various pieces.  You must be comfortable with abstraction to handle this type of question.  2010 had the CookieOrder question and 2012 had ClimbInfo.  Sparse Array from 2015 was another cool List of classes question.  I think making something like Sparse Array but with a list of lists is quite possible.

2.  Make a Class from scratch – Every student should know how to make a class, implement an interface, and extend an abstract class.  In 2014, the Trio question marked the return of the interface FR which means an abstract class Free Response can’t be too far behind.   Be prepared create an interface / abstract class in part A and then use Part A to make a new class in Part B as was the case in 2015.  Be prepared to override some methods and make something new from something old.  You know you will have to create a complete class or create something really similar and it will be super!   Look at the 2005, 2006, and 2007 AP FR questions if you want some past FR examples.

3.  Processing an Array or String – String – String –  I missed the boat on the Strings last year as there were a whopping 3 questions that did something with Strings.  They will not get me this year as I am including both arrays and Strings here.  I know it is kinda like cheating, but I am covering my behind this year.  I predict a basic algorithmic array or string question.  Look back at BatteryCharger from 2009 or the Sound question from 2011.  Those questions are pretty good algorithm questions.  Find a particular something in an array or string.  I am also betting part A must be called by part B and / or part B must be called by part C.

4.  Matrices – Be on the lookout for another matrix of classes question.  I predicted this in 2013 and was wrong, but I went with it again in 2014 and hit pay dirt as the there was a Student[ ][ ] question on the exam.  Finally!  There will certainly be a matrix question again this year and with PictureLab being one of the AP CS A Labs, I am thinking a matrix of references is again a distinct possibility.

I will post follow-up comments after I see the 2017 Free Response questions.  Hopefully, my predictions will be right on this year.  I have been pretty close in the past, but this year is a new year.

A few review points to emphasize before the exam.

Multiple Choice [ 90 minutes ] –   Manage time and get through the 40 questions more than once.  Skip the longer questions the first time through.

Free Response [ 90 minutes ] – Answer the easiest question first and do not leave any questions blank.  Make sure to return and to call part A from B if the question says you MUST do that.

If you want some great reviews the AP Computer Science A Exam,  I have quite a review slides posted   AP Exam review slides   with Java code projects ready for students to complete.  The Java code projects have runner files and everything students need to test student hand-written free response code.  Feel free to use them to help your students.  It is very beneficial for students to write the free response code on paper and then type it up.

Do you need great AP Computer Science Curriculum that covers all of the topics I have listed above?  Do you need labs, slides, tests, quizzes, and worksheets that cover arrays, arrays of references, ArrayList, ArrayList of References, Matrices, Matrices of References, Interfaces, and Abstract Classes? Take a look at the A+ Computer Science Curriculum.

The A+ Computer Science Curriculum was designed to provide students with multiple opportunities to master the core concepts covered on the AP Computer Science A Exam.

If you like my humor and want to spend a few days hearing more about how to get students ready to ROCK the AP exam, check out my workshops going on over the summer or email me about setting up a custom training at your school or for several schools.  I will show you how to get any student ready to make a 5!

High School Computer Science Contests

Looking for a way to get kids excited about learning Computer Science?
Take your students to a programming contest.

Why?  They learn teamwork and how to problem solve under pressure.
Also, they get a chance to dominate the planet.  Who doesn’t like winning?

Check out HP Codewars and Codequest.

Also, ask your local colleges to see if they host a high school contest.
Many college ACM groups host high school programming contests.

A+ Computer Science Contest Dates Page

Host your own high school contest.  Why?  It is fun and you will be helping out others in your area.

Need help preparing your team for contests?  A+ has a ton of great stuff to help.
Want to host a local high school contest?  A+ has a ton of great stuff to help.

Email me at and I will help you find a local contest or help you learn how to host one in your area.

Computer Science contests rock!

AP Computer Science 2 Day Workshop – San Antonio, TX – Feb 17-18

There will be an AP Computer Science 2 day workshop in San Antonio, Texas on February 17 and 18.

Lots of great sessions will be presented.
*   How to get your students ready to make 5s
*   Introducing OOP with Greenfoot
*   Teaching Arrays, Lists, and Matrices early
*   Lots of discussion of best practices

Email me if you have any questions.


How much can you make if you know a certain programming language?

Here is cool article on what it pays if you know how to program in a particular language.

It seems students always want to know which languages they need to learn and why.
This will definitely provide some of that information.


2016 AP Computer Science A Free Response Solutions

Well, I was tardy in getting my predictions up on the blog.  Too many irons in the fire.

Here is a quick summary of my predictions.
1 – Class Creation with Inheritance  [ I was close, but I figured Abstract class ]
2 – ArrayList of Some Class [ This one is easy as its on the exam every year ]
Just happened there were several parts this year with ArrayList of Some Class.
By Some Class, I mean Some Class that is new to the testers like CookieOrder or ClimbInfo.
3 –  Matrix of Some Class [  2014 had the Matrix of Student  –   Crossword was fun this year ]
4 –  I said String or 1D Array [  Good lord I had no idea there would be 3  YES 3 String Questions ]

I was pretty close on several of my predictions.
I was not even close on the number of STRING questions.
Do not get me wrong – I love me some STRINGS, but good lord – Really?  3 Questions with Strings?  Enough about that.

Check out my A+ curriculum materials if you need awesome support for any of the concepts tested on the multiple choice or Free Response.

I have posted slides with my solutions and a java student project that has shells and no solutions.  This project will allow students to punch in their code and see if works.

There are review slides for the AP Computer Science A exam for years 2006, 2008, 2010, 2011, 2012, 2013, 2014, and 2015.  There are student java projects in place now for many of the AP Computer Science Free Response sections.

Have a great summer and check out my workshop offerings if you are free this summer.

I also do local workshops for schools and school districts.  If you need specialized local training, email me and we can discuss specifics.

Computer Science Contest Materials

Looking for the BEST Computer Science Contest Prep Materials?
Looking for Computer Science practice problems with solutions?
Looking for Computer Science practice multiple choice questions with explanations?
Looking for live practice programming problems with tutorials that are auto-graded?
Looking for materials to host a Computer Science programming contest?

A+ Computer Science has the BEST Prep Materials for Computer Science Contests.
Get the 2016-2017 Order Form


High School Programming Contests Rock!

What are high school programming contests?

High School programming contests are team events where students from different schools attempt to solve as many problems as possible in a 2-4 hour time frame.  Most teams consist of 3 members and are allowed to use 1 computer.

Why should I take teams to programming contests?

Well, it is a great way to get more students interested in computer science.  It is great team building and it is a ton of fun.  If you have teams that win, that is even better.  Winning a contest or two can really pump up your stats on that college application.

Which contests are out there that my students can attend?

HP CodeWars is fun and growing every year with new sites popping up all over.
Lockheed Martin Code Quest is another contest with sites all across the planet.
Check out my contest page with links to many contests in Texas and beyond.

Can I get materials to help my teams prepare or to host a contest at my school?

Sure.   Check out my contest materials page for information on materials to prep for contests, live online programming problems, and contest hosting materials.  Hosting a local contest in your area is really fun and a great experience for students.  It is also a great way to promote Computer Science and get more schools involved.

If I have to give up lots of my time to get students ready to compete and to take them to contests, is it worth it?

It is very well worth it.  Contests are great opportunities for students to learn more about team work and problems solving.  Students learn many cool algorithms preparing for contests that often show up in technical interviews.  Several of my former students that have interviewed with big software companies were asked to explain how to solve problems in technical interviews that we worked on preparing for programming contests.  I have been fortunate to have coached several state championships in my 15+ year of coaching Computer Science teams.  Those experiences are well worth the time spent making that happen.

2016 AP CS 2 day workshop

Judy Hromcik and I will be conducting an AP Computer Science 2 day workshop on January 22-23 in Richardson, Texas.

We will cover the new AP CS A Labs, changes to the AP CS A exam, Tips to get all students to make a 5, and lots of general information about AP Computer Science A and a bit about AP CS Principles.

We will cover lots of cool AP Computer Science topics.
Download the agenda.

You can find registration information here.

Email me at if you have questions.

Hope to see you there.


Looking for Awesome AP Summer Institutes for Computer Science?
Check out my workshops page.