FRQ 3 Array and ArrayList

Last question!! Question #4 has students analyze and manipulate data in a 2D array. Sometimes these questions incorporate array as well. This question has both a part A and a part B.

Be sure to attempt each part.

As mentioned in prior posts, be sure to always attempt each part. Sometimes, students will find that they understand the directions for part B better or find that part B is easier. Students might also find that while solving part B, the solution to part A becomes clearer.

You have to traverse the 2D array.

This traversal could be in row major order or in many different patterns.

In 2024, the question doesn't traverse the structure. It accesses individual elements in a pattern.
In 2023, the question traverses a given column in part A. In part B, it traverses by starting at the bottom right and moving to the left and continues each row from right to left.
In 2022, part A traverses in row major order and part B traverses in column major order.
In 2021, part A traverses a given row and in part B traverses row column, but skips some columns.

Call methods for the newly introduced class.

You may be given a new class for the data being stored in the 2D array. This will likely require you to access the data from the 2D array and then call methods from the new class on that data.

Use the methods and data provided for you.

If you are provided a new class, the data and methods provided are meant to be used in the solution. Be sure to pay attention to provided:

instance variables
constructors
methods
methods return type
methods parameters.

Know the standard algorithms.

In the AP CSA Course and Exam Description, there are some standard algorithms listed for manipulating 2D arrays. Provide your students with a lot of practice with these standard algorithms as well as modifying these standard algorithms. Here is a list of the algorithms your students should have experience with:

determining a minimum or maximum value
computing a sum, average, or mode
determining if at least one element has a particular property
determining if all elements have a particular property
accessing all consecutive pairs of elements
determining the presence or absence of duplicate elements
determining the number of elements that meet a specific criteria
shifting or rotating values from left or right
reversing the order of elements.