Questions:

1. The class Boid represents a single movable object that can be drawn and run as a thread. The boid can move around the bounds of a panel with specified velocities in each of its x and y directions. Each Boid needs to know the position and velocities of the nearby (neighbouring) boids around it. However the class is not thread safe. Make the necessary changes to make this class thread safe and avoid any concurrency problems.

2. Using the following UML class diagram create a data structure calledBoidFlock that holds Boid objects in a list. The default constructor just creates an empty flock and initializes the boidList using an appropriate data structure, where the 2nd constructor creates a flock with the specified number of boids to start with. The addBoidToFlock method should add a new Boid to the boidList using random positions (0 - panel width and height) and velocities ( Boid.MAXSPEED), it also needs to pass itself as a reference to the newly created Boid, then should start the object up as a thread. The removeBoidFromFlock should remove an arbitrary Boid object from the list, also stopping its thread execution, destroyAllBoids should stop all boid threads running and clear the list, getNumberOfBoids returns the current number of boids in the list. The getNeighbours is used to return a new list of all the neighbouring boids that the boidToTest object has (excluding itself). A boid is a neighbour if its x and y value is within the DETECT RADIUS of the boidToTest parameter. Make sure this class uses generics where appropriate and that it is thread safe.

A boid with co-ordinates (x0, y0) is a neighbour to another boid (x1, y1) if: (x0 -x1)2 + (y0 -y1)2

3. Prepare a simple GUI called BoidGui to test the BoidFlock and Boid class which should display an entire flock of boids that move around within a panel bouncing off the walls. The GUI should repeatedly update its display by drawing the boids at fixed time intervals.. Add buttons for adding and removing boids or clearing the screen. Add sliders for manipulating radius detection and separation, cohesion and alignment weights of the boids.

4. Suppose an interface called RandomObtainable has been written for collections from which a random element should be obtainable. It has a method getRandom which should return an element randomly selected from the collection, and a method removeRandom that should try to remove a random element from the collection and insertRandom which inserts the element into the collection at a random location between zero and the size of the collection (inclusive). The getRandom should throw a NoSuchElementException if the collection is empty.

Extend the ArrayList class so that it implements this interface, and test it with a driver main method. At the top of your class in the header comments state what the asymptotic complexity is for each of the methods and why? If instead your class extended LinkedList, what are the asymptotic complexities?

Attachment:- java.zip