AP计算机科学A 2016年真题 附答案和评分标准 AP Computer Science A 2016 Real Exam with Answers and Scoring Guidelines.pdfVIP

AP® Computer Science A 2016 Free-Response Questions © 2016 The College Board. College Board, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks of the College Board. Visit the College Board on the Web: . AP Central is the official online home for the AP Program: . ® 2016 AP COMPUTER SCIENCE A FREE-RESPONSE QUESTIONS COMPUTER SCIENCE A SECTION II Time—1 hour and 30 minutes Number of questions—4 Percent of total score—50 Directions: SHOW ALL YOUR WORK. REMEMBER THAT PROGRAM SEGMENTS ARE TO BE WRITTEN IN JAVA. Notes: • Assume that the classes listed in the Java Quick Reference have been imported where appropriate. • Unless otherwise noted in the question, assume that parameters in method calls are not null and that methods are called only when their preconditions are satisfied. • In writing solutions for each question, you may use any of the accessible methods that are listed in classes defined in that question. Writing significant amounts of code that can be replaced by a call to one of these methods will not receive full credit. 1. This question involves the implementation and extension of a RandomStringChooser class. (a) A RandomStringChooser object is constructed from an array of non-null String values. When the object is first constructed, all of the strings are considered available. The RandomStringChooser class has a getNext method, which has the following behavior. A call to getNext returns a randomly chosen string from the available strings in the object. Once a particular string has been returned from a call to getNext, it is no longer available