Lab 5: ADTs and the JobManager

Overview

This lab activity focuses on the design and implementation of an abstract data type (ADT) that we shall call JobManager. A JobManager is responsible to managing a set of jobs, which are identified by integer IDs from 1 to n. A JobManager also maintains a set of Robot objects that are responsible for completing these jobs. The JobManager ADT's operations enable its user to manage the set of Robots and the assignment of jobs to thoseRobots.

Operations

A JobManager is seeded with n (the number of jobs it is managing). Each of these n jobs are initially “unassigned” (i.e., not assigned to a robot). One can then add Robots, assign jobs to the Robots, and move jobs among the Robots.

The principal operations that the JobManager ADT supports are as follows:

• Create Instance JobManager(int n) → Create a new JobManager instance with n jobs with all IDs in [1, n].

• Add robot addRobot(Robot robot) → Add a new robot to the pool of robots that can complete jobs.

• Check has robot hasRobot(Robot robot) → Check if robot exists in the pool of Robots maintained.

• Remove robot removeRobot(Robot) → Remove a robot from the pool of robots; all jobs assigned to the robot that was removed will be “unassigned”.

• Assign jobs assignJobs(Robot robot, int jobId) → Assign all unassigned jobs with id $\le$ jobId to robot.

• Check if job is assigned isAssigned(int jobId) → Checks if the job with id = jobId is assigned to any Robot in the pool.

• Move some jobs moveJobs(Robot srcRobot, dstRobot, int jobId) → Move all jobs with id $\le$ jobID from srcRobot to dstRobot.

• Move all jobs moveJobs(Robot srcRobot, dstRobot) → Move all jobs from srcRobot to dstRobot.

• Get assigned robot getRobot(int jobId) → Identify the Robot that is responsible for the job with jobId as its id.

• Get highest priority job assigned to a robot getHighestPriorityJob(Robot robot, int jobId) → Assuming that the job id indicates priority (higher id ⇒ higher priority), obtain the highest priority job assigned to robot with job id $\le$ jobId.

• Check equality equals(Object o) → checks for equality with another object based on a specified notion of representation equality.

• Get hashcode hashCode() → returns a hashcode that obeys the contract with equals() and that tries to minimize hash collisions through a Robot id-aware hash function.

Your Task

Your task is to implement the JobManager ADT in Java by implementing all methods corresponding to the Operations outlined above according to their respective specs detailed in the JobManager class file. You cannot change the spec of any methods, and you cannot change the Robot class in any way.

Grading

You will answer some questions on PrairieLearn and you will submit your implementation to PrairieLearn and GitHub.

For the implementation aspect of this assignment, we will grade your GitHub submission, with more tests than are used on PrairieLearn. But the tests on PrairieLearn should offer some guidance. (And do not worry about the points on PrairieLearn for the programming question; they do not matter.)

This programming task is worth 6 points and the other questions on PrairieLearn are worth 3 points.