2011 AP CS A Exam Free Response Solutions

Some of the 2011 AP Computer Science A Free Response problems are of above average difficulty.

The Sound method trimSilenceFromBeginning is straightforward. It can be made considerable more complex than necessary if the algorithm is not thought through before starting the code.

The AttractiveCritter question (from the old GridWorld Case Study) requires selecting the correct Critter methods to override. The implementation code is of moderate complexity.

The FuelDepot method nextTankToFill is a simple twist on finding the minimum. The moveToLocation method is straightforward but requires adhering to the moveForward method precondition.

The RouteCipher method encryptMessage prompt explicitly describes the required algorithm. Implementing the algorithm as described is straightforward. Many students misread the prompt and write an inappropriate response (such as attempting to implement the encryptBlock method).