I have a class "ExecuteJob" which has Print Q in the form of Priority Q.
You can keep adding job to the Q by calling one of the method in the class. However, and object cant do things simultaneity can it? While im adding a new job to the print queue, can it be executing and existing job in the print Q.
To achieve that, I would need to implement process and threads? I believe am I right? So that adding a job is independent to being removed?
I am in the process of implementing Priority queue, as I understand that there are many data structures you could use to implement. I implemented it with the an array, which it works absolutely fine. However I have limitations on what collections I can use from the collections classes. I fact I cant use any of the collections classes. Meaning I cant use array.
I’m trying to implement Priority Queue using heap. And implementing heap using binary trees. But however I have a few questions which I need to clarify and I cant think of any other way of resolving it. Ofcourse I can implement my own simple array class using linked list.
Inserting into heap would be quite simple, as I just need to find the right last position from left to right leaf to insert the node into the tree. However after inserting, you may want to make sure that leaf node values are > than root node. Therefore, the root node will always be with the highest priority.
I call these steps where you compare from top down as bubbledown and bubbleup. To do this I really need a for each node within the treee node to have attribute pointing to its root node. So in case of bubbleup I always have a pointer for a given node to its root, without it would mean I would to traverse through the entire tree to identify its root. Which I believe is very inefficient.
Or have I taken this completely wrong? Or is it the case that heap are only best with arrays and therefore use array (by implement it using linked list?)
I'm working on a lab for my class. I need to create a Priority Queue in Java using an array list. The kicker is that each node has to have a "handle" which is just an object which contains the index of of the node that it's associated with. I know that sounds weird but we have to implement it this way. Anyway, my priority queue seem to work fine except the handle values apparently aren't updating correctly because I fail the handle test. Also, I run into problems with handles only after extractMin() is called, so I figured the problem would be somewhere in that method but I've been through it a million times and it looks good to me.
Here is my Priority Queue Class:
package lab3; import java.util.ArrayList; /** * A priority queue class supporting operations needed for * Dijkstra's algorithm. */ class PriorityQueue<T> { final static int INF = 1000000000; ArrayList<PQNode<T>> queue;
[Code] ....
I can post the tests too but I don't know if that would do much good. Just know that the queue works as is should, but the handles don't point to the right nodes after extractMin() is utilized.
My assignment was to create a priority queue for Airline Passengers. Here is what I have done so far:
//Driver
package priorityqueuestandby; import java.util.NoSuchElementException; import javax.swing.JOptionPane; public class PriorityQueueStandBy { public static void main(String[] args) {
[Code] .....
So the part that I cant figure out is:
When a standby passenger is to be enqueued into the priority queue, it must be done so that at the moment of each dequeue operation, the item at the head of the queue is the standby passenger with the longest longevity, and also so that passengers with the same longevity are dequeued in a first-come-first-served fashion.
he says that we need to "Make your program so that it extends Comparable and implements the compareTo() method properly..."
So I was looking at the Comparable class and I could't find a compareTo() method... I am not confident I know how extends works either. I am assuming I need a new class if I am going to be extending another class. Right now I am taking in longevity as a String and converting it to an int because my last ditch effort is going to be to set up a loop that will organize longevity into a/an circular array based on the size of the incoming integer.
I was given some code by a professor to add some features to as part of an assignment. However, the code itself doesn't seem to work.
import java.util.HashSet; import java.util.InputMismatchException; import java.util.PriorityQueue; import java.util.Scanner; import java.util.Set; public class DijkstraPriorityQueue
[Code] ....
The method to find minimum distance is nonfunctional...I receive an error that the types are incompatible. I can't do the assignment if the base code doesn't work to begin with...
how to setup a program that simulates the progression of a line over time.The scenario involves a bank and 5 tellers. There is one line of customers that starts off with an initial length of 20. Every minute, 10 more customers are added to the line. As this is meant to be a FIFO queue the first 11 customers in the line will be distrusted among the 5 bank tellers as follows: Teller #1 will process 1 customer per minute, Teller #2 and #3 can each process 2 customers per minute, and Teller #4 and #5 can each process 3 customers per minute. Therefore, the first 11 customers in line will be processed within the first minute of the programs execution.
Unfortunately, I am not sure how to attack this thing. I am thinking that I need to setup a queue for the initial 20 customers and an array for the 10 customers that will be joining the line every minute. However, I am not sure how I can set this up to work automatically.
I have been working on this Java Gui program and i cant get it to print to the textbox correctly.i originally had it displayed in a dialog window but it would print one integer a time in a seperate window.
I'm doing an assignment where a method receives a Queue as a parameter then convert it into a stack, I made it but now I want to try it in my main, but how can I do this? there's no toString and I cant use a for loop because I'm using a queue and not an array. This is the head of my method:
I have an assignment to complete where I have to develop a Java Console application in Eclipse which accepts regional zone information for premises based upon addresses provided. The program needs to figure out which geographical zone each customer lives in and based upon their age, set a priority rating.
The zones (which is the Belfast and the directions) and sub-zones (which are the Postcode such as "BT1" are:
1.Display a count of addresses within a user defined geographical zone. 2.Display all information for customers within a user defined geographical zone. 3.Display a complete set of captured data. 4.Display a prioritized list of customer details within each geographical zone. 5.Display a count of customers within each geographical zone.
Below is the code I have created so far for it.
package assignment1;
import java.io.BufferedReader; import java.io.InputStreamReader; public class Assignment1 { private static InputStreamReader input = new InputStreamReader(System.in); private static BufferedReader reader = new BufferedReader(input);
[Code] .....
The main issue I'm having is to make sure that data like address and customer counts, and customer details appear only for the selected areas.
I was thinking to make a game where two cars are going to race against each other. I already have two gif pictures which are the cars. I do now have a background and a racer track. So we can start from here.
I have made a object with construction which I called Racers. Inside that, i wrote a PaintWindow (Where the window and much more is inside), -car1, -car2. All these is private. So I made something like this now:
package p2; public class Race { private Object window; private Car car1; private Car car2; public Race(PaintWindow window, Car c1, Car c2) {
[Code] .....
But the problem is now that im kinda lost and I dont really know what to write anymore. How can I get a for example a green background on the whole PaintWindow with two Racers tracks and inside the racers tracks (Each car have each track) does it have to be cars. So I need to somehow import the cars inside it too. But thats the problem I need. that I dont really know what more to do. To make it easier, I have a Main-method in another class.
public static void main(String[] args) { PaintWindow window = new PaintWindow(); Car c1 = new Car(new ImageIcon("C:/Users/Sarah/Desktop/CarBlue.GIF")); Car c2 = new Car(new ImageIcon("C:Users/Sarah/Desktop/CarRed.GIF")); Race race = new Race(window,c1,c2); race.action(); if(args.length>0) { Paintwindow.pause(2000); window.dispose();
I'd like to learn more in Java security, namly Kerberos and SSO. The question is weather I have too weak laptop. I have 8 GB ram. How many virtualbox instances od I have to run in order to JAAS, SSO kerberos demo to simulate. For instance VM with Windows 2008 Server -> 3 GB RAM, Centos VM -> 1GB. Is 8 GB RAM in my laptop not too little?
BTW
I do not have yet experience in SSO/Kreberos but I want to know what to do in order to simulate and exercise.
I'm a student designing and developing an Air Traffic Control (ATC) system for incoming aircraft, mainly implementing the part which handles the queuing system for approaching aircraft.
So what I want to do is have a method that allows me to use the callRandomNumber method so that the matrix location with that random value is marked true for all of the boards.
I am writing a simple program to simulate a traffic light. What I want is to make them glow after each 1 second, one by one. For example: Firstly Red, then after 10 seconds, red will be put to off and yellow will start glowing and then accordingly green. This process shall continue incessantly (Just for experimental purpose). I have some arrangement done but could not figure out how to put them together in run() method of Runnable interface. I know how interthread communication works. But could not find any logic in this case when three threads will run together.
import java.awt.*; import java.awt.event.*; import javax.swing.*; public class TrafficLight extends JFrame implements Runnable { JButton red, green, yellow ; TrafficLight()
I'm very new to Java (I literally started learning it yesterday) and I've been working on a simple program that's meant to simulate interactions between optics objects and light rays.
Everything has been going really well, except that my mirrors only reflect the first ray that comes in contact with them.
Here's a screenshot : 2014-09-13 at 7.39.23 PM.jpg
I wrote 7 classes:
Main class to create the optics objectOptics class. the most important class that uses a recursive function to detect the nearest intersection point of a ray with the nearest optics object. It then calculates a reflected ray and inputs it back into the function until no intersections are found or the max recursion depth is met.Ray. creates a rays (in parametric form O + tD where O is the origin, D is the direction and t is a non-negative scalar)Object. empty abstract class used for polymorphism (so when i add more optics objects like prisms and lenses they'll share the object type)Mirror. Basically a line segment created with the Line classLine. Creates a line segmentDraw. JComponent with paintComponent function that loops through an array of shapes and draws them to the screen.
What I know so far is that the problem boils down to the checkRay() function in the Optics class. When a mirror has already reflected a ray, the line:
Intersection sec = new Intersection(ray,(Mirror)obj);
creates an intersection with a null point.
I debugged it line by line and found the problem was that my variable 't' (that is the parameter for the parametric line which represents the mirror) in the Intersection class got big values when it's meant to be between 0 and 1 (since it's a line segment), which resulted in the function returning null (as it should when 't' is not between 0 and 1).
I've confirmed with tests that this has nothing to do with the specific mirror or angle of incidence. It only occurs when a mirror has already been intersected with by a ray.
I've found out that my function:
public PVector getNormal(PVector D){ D.normalize(); return new PVector(D.y,-D.x); }
Changes the value of the 'D' PVector of the mirror inside my 'objects' ArrayList. How can it access the private PVector 'D' from outside the Mirror class? This normalization to the direction vector is what causes the Intersection class to return null the second time around!
The problem was that in the getNormal function, the input vector argument was a reference to the 'D' vector for the mirror in my 'objects' ArrayList so the .normalize() function acted upon the original vector, changing it's value and screwing things up. The two classes I talked about:
Optics: (note line 64. this line returns a null intersection when it shouldn't)
package ofer.davidson; import java.util.ArrayList; public class Optics { //Arrays to store all the optics objects and rays that are created ArrayList<Object> objects; ArrayList<Ray> rays;
I am making a elevator simulator for my class. It needs to be "event time". I am having trouble understanding how I can make an "event time" simulator. Initially I was using a while loop to run a clock time simulation of x seconds for each event, until I ran into a concrete wall and had to call another method which took X seconds, while still needing to execute code.
An example of what I did is:
Spawn person -> person.goToElevator (Takes x seconds) - > person.waitForElevator (Until elevator arrives, x seconds). While this is happening, I needed to create another person and do the same thing, this will add another to the queue if the first person is still waiting. Etc etc, you get the point.
We have not learnt about multi threading, that is the next assignment.
Here is a quote from my lecturer:
"That's right, it requires multi-threading which we're not doing in this paper. Here's a solution that can work:
The person waiting for the lift and then doing lots of other things should do all that in a fraction of a second. So, you don't let the person really wait. Instead, you will set a timestamp in the future in the person object that "he's busy till that time". In all other steps in your simulation you will first check if a person is "busy" (i.e. has a timestamp in the future). If so, you can't use this object, otherwise, you can.
How does it create a bigger queue? Outputs I would have in my final simulation would be, averageQueueLength, numOfPeopleInBuilding etc.
I am attempting to create a 2d game that has a realistic space simulation. The map is supposed to be set so that you are looking from the top down. The problem I am having exists in my interaction between the sun and a planet. Simply put, the planet will only move in a single diagonal direction without ever changing direction. The formulas I am using are F=(G*M1*M2)/D^2 and A=F/M. The code below is simplified.
Things I have already tried: 1. Setting G to negative 2. changing the order of the subtraction in determining D 3. some weird pythagorean theorem thing someone suggested
I need to do a simulation on the assembly code level by writing a mini-compiler for each ISA, i.e., 4, 3, 2-Address Architecture, Accumulator Architecture, Stack Architecture, and Load-Store Architecture.The input to the simulator is a segment of C program:The basic sample segments of C code are:
Basically the class is supposed to have a static variable that keeps track of the number of companies (numberOfCompanies) that have been created and a static method that returns the value of this variable. I need to have a constructor and a method to addEmployee, a method to printCompany, and a toString method. The addEmployee method will check that there is only 1 salesperson, 2 designers, and 4 manufacturing persons at a time and will check that there are no more than 7 employees of the company.
The addEmployee method will return a String indicating what the error is (i.e. "There is already a sales person in this company") or a null if the employee was added. If attempting to name a third company, an error message will be shown. what i have so far but my print company mmethod returns null company class :in which i am obliged to use inputdialog because it says that it cannot return void when i use the showmeassage diaolog.
company class:
import java.util.ArrayList; import javax.swing.JOptionPane; public class Company { private ArrayList<Employees> list ; private static int numberOfCompanies;
[Code] ....
error message when print button is clicked:
Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: JOptionPane: parentComponent does not have a valid parent at javax.swing.JOptionPane.createInternalFrame(Unknown Source) at javax.swing.JOptionPane.showInternalOptionDialog(Unknown Source) at javax.swing.JOptionPane.showInternalMessageDialog(Unknown Source)
