How does reference counting manage memory allocated objects? When can it fail to reclaim objects?

IN java  YOUR TASK IS TO IMPLEMENT A JAVA APPLICATION WHICH WILL FUNCTION AS A TYPE OF STUDENT REGISTRATION DATABASE WHICH WILL ENABLE AN ADMINISTRATIVE USER TO EITHER CREATE OR DELETE A STUDENT ACCOUNT IN THE DATABASE IN ORDER TO STORE THE FOLLOWING DETAILS:- (1)THE STUDENT’S NAME, (4) THE STUDENT’S ID NUMBER, (3) A LIST OF THE COURSES WHICH THE STUDENT HAS TAKEN ALONG WITH THE CORRESPONDING GRADES FOR THESE COURSES. NOTE: WHEN THE VALUE -1 IS ENTERED, THE APPLICATION WILL TERMINATE. please check the attached image

// Assume system starts allocating memory from location Ox20 char status; int id: struct { char task[ 9 ]; score[ 7 ]; int } sample[ 4 ]; Enter the memory location address in hexadecimal for "sample[ 1 ].score[ o ]": Ox

Please refer to this textbook: “A. Silberschatz, P. B. Galvin and G. Gagne, “Operating System Principles,”7th Edition, John Wiley & Sons Inc., 2006.”   And answer the following questions: Question:15 A system has the following blocks queued for writing: 8000, 3000, 5000, 2000. The most recently written block was 4500. The block read before that was 2500. (a) What sequence of writes will a C-SCAN algorithm generate? (b) What sequence of writes will a SCAN algorithm generate? (c) What sequence of writes will a FCFS algorithm generate? (d) What sequence of writes will a SSTF algorithm generate? (e) What sequence of writes will a LOOK algorithm generate?