AP CSA FRQ Guide
2006 FRQ 4: DropGame
Find the lowest empty location in a selected column, then determine whether a hypothetical dropped piece would match the colors of three neighboring pieces.
Legacy Marine Biology Board Analysis22 minute targetMarine Biology Simulationlocationsneighbor traversalobjectslegacy
Skills Tested
What this FRQ is really practicing
Marine Biology Simulationlocationsneighbor traversalobjectslegacy
Review these topics before attempting the problem.
Starter Approach
How to begin with your own plan
- 1Part A: return the empty location with the largest row index in the given column, or null when the column is full.
- 2Part B: use dropLocationForColumn to identify the hypothetical landing location; return false if no location is available.
- 3Use the environment neighborsOf method to inspect adjacent occupied locations and determine whether three neighboring pieces match pieceColor.
- 4Compare colors by their values and avoid treating diagonal positions or empty locations as matching pieces.
Attempt the problem before opening the solution.
Common Mistakes
Mistakes to watch for while writing
Returning the topmost empty location instead of the one with the largest row index.
Counting diagonal positions instead of the environment-defined neighbors.
Reading a piece color from an empty location or failing to handle a full column.
Self Check
Review questions before you submit
Checks whether a candidate location is empty.
Choose the empty location with the largest row index.
Returns null for a full column.
Do not construct an invalid row outside the environment.
Uses the supplied landing-location helper.
A null landing location means no winning drop is possible in that column.
Inspects environment neighbors and piece colors.
Only occupied neighboring locations can contribute a color match.
Practice Links