2007 AP CSA FRQ 3: StudentAnswerSheet
Topic: ArrayList & Scoring Algorithms
Skills Tested: Parallel ArrayList traversal, scoring logic, finding maximum
Curriculum Alignment: Unit 4 (Data Collections) (2025-2026 AP CSA)
Points: 9 | Time Estimate: ~22 minutes
Study This Topic: Unit 4: Data Collections Complete Study Guide
Part (a)
Write the getScore method that calculates a student's score: +1 for correct, -0.25 for wrong, 0 for blank ("?").
Try It First! Attempt to solve this part before viewing the solution.
Solution
public double getScore(ArrayList key)
{
double score = 0;
for (int i = 0; i < key.size(); i++)
{
if (answers.get(i).equals(key.get(i)))
score += 1;
else if (!answers.get(i).equals("?"))
score -= 0.25;
}
return score;
} Part (b)
Write the highestScoringStudent method that returns the name of the student with the highest score.
Solution
public String highestScoringStudent(ArrayList key)
{
int maxIndex = 0;
for (int i = 1; i < sheets.size(); i++)
{
if (sheets.get(i).getScore(key) > sheets.get(maxIndex).getScore(key))
{
maxIndex = i;
}
}
return sheets.get(maxIndex).getName();
} Key Concepts
✓ Use equals() for String comparison, not ==
✓ Blank answers ("?") don't affect score
✓ Standard find-max algorithm: track index of maximum
✓ Start loop at 1 when comparing to index 0
Common Mistakes to Avoid
✗ Using == instead of .equals() for String comparison
✗ Wrong penalty calculation (should be -0.25, not -0.5)
✗ Not handling blank answers correctly
✗ Returning score instead of name in part (b)
Official College Board Resources
About the Author: Tanner Crow is a certified AP Computer Science teacher with 11+ years of experience.
Last updated: January 2026