I need a Example of a Hash Mapping Algorithm in Java. This Mapping Needs to do the following:
Map an Array of Strings, to integer values which correspond to each fruit
private String[] Fruit = {"Apple","Orange","Pear","Grapes"};
Apple: 1 + 1
---------------
Orange: 1+ 2
---------------
Pear: 1 + 3
---------------
Grapes: 1 + 4
---------------
I not sure where to start at the Moment...
I got this code from wikipedia when trying to learn about the radix sort algorithm now I understand that the algorithm sorts by significant digits but it's the code that I'm not too sure about for instance the series of for loops at the bottom what exactly is going on there and why is it mod by 10? Also why are there three different integer arrays a, b, and bucket?
public static void radixsort( int[] a, int n) {
int i;
int digit = 1;
int[] b = new int[n+1];
for (i = 1; i < n; i++)
if (a[i] > a[0])
a[0] = a[i];
[Code] ....
I'm finding common elements in a collection of arrays. This is my code so far.
import java.util.ArrayList;
import java.util.List;
public class CommonElements //< T extends Comparable<T> >
{
Comparable[] comparable;
Comparable[] tempArr;
Comparable[] tempArr1;
Comparable[] newArray = new Comparable[tempArr.length];
int comparisonCount;
[code]....
I'm using this method to sort through my array. The method accepts a collection of arrays (of varying length and of any type) as input, the algorithm input should be no greater than n(k-1). I know I can solve it using a quadratic algorithm, but it won't meet the requirement of the assignment. I did have an idea of storing all my algorithm in one giant array. After storing as one giant array I was going to sort it. After sorting I was going to compare each array side by side and see if they are the same. Here is note my teacher provided.
Note About Testing You will need to develop several sets of test collections for testing your algorithm. The grading rubric mentions covering the case where all the test collections have the same length, as well as covering the case where the test collections are of different lengths. You will also need to think about what constitutes the worst case scenario for this algorithm, since only that scenario will make your analysis of total comparisons performed a meaningful one. You can use the formulas in the grading rubric to tell you how many comparisons you should expect in the quadratic and linear cases. For example, if you have 5 total collections (1 query collection and 4 test collections), each of which contains 10 elements, the total number of comparisons performed in the worst case should be: (k - 1)N2, which for k = 10 and N = 10 is: (5 - 1)102, or 400 comparisons. For the linear algorithm, you should only have N*(k - 1), which is 10*(5 - 1), or 40 comparisons.
Here is Q/A that my teacher provided:
1. Are the elements in the collections already sorted?The input collections may or may not be sorted. Don’t assume that they are sorted.
2. Can I sort the elements in the collections? Am I supposed to sort the elements in thecollections?Yes, you can sort the elements in the collections. It is not required that you do so, however..
3. If I sort the collections, should I count the element comparisons that are performed by the sorting algorithm?No. The only element comparisons you should count are the ones that are directly used to find the common elements. Ignore comparisons performed by any sorting algorithms you use.
4. How do I extract an individual collection from the Object[] collections argument of the findCommonElements method?You will need to typecast each collection as type Comparable[]. For example:Comparable[] currentCollection = (Comparable[])collections[i];
5. Why are we using a one-dimensional Object array instead of a two-dimensional array of type Comparable (e.g., Comparable[][])?In Java, arrays are treated as objects, so only a variable of type Object[] can contain arrays. A variable of type Comparable[] can only contain Comparable elements, not arrays. A variable of type Comparable[][] also can only store Comparable elements. Although it is possible to organize the elements such that all the elements at indexes [1][i], for example, are considered to comprise a collection, this is not the same as having an array that contains other arrays. The additional bookkeeping is required to keep a 2D array organized is more complex than simply performing the typecast described above.
6. Can I use other data structures besides arrays; e.g., HashMaps?No. Although it is easier from a programming perspective to use higher order data structures like HashMaps to find common elements, using these structures simply hides the details. If you were to examine the implementations of those structures, you would probably find that they use relatively inefficient algorithms such as sequential searches to find elements. Additionally, if you use library components, you have no way of counting the number of comparisons performed, since you don’t have access to the source code of those components.
7. Is this a trick question? I can’t think of any way to get below NlogN comparisons.It is not a trick question. It is possible to solve this problem using a number of comparisons proportional to (k – 1) * N.
I have been looking around and I cannot seem to find which algorithm java uses for its sort method. Merge, sort etc.
While I am on the topic BinaryTree is a balanced heap right?
Are there any libraries for depth or breath first search?
Is the ArrayList a double linked list?
I have to write the Insertion Sort Algorithm using Java codes and at the same time find the time of execution for different sizes of array, filled with random numbers. If I try to show the numbers inserted into the array randomly, they don't appear at the console.
import javax.swing.JOptionPane;
public class Insertion {
public static void main(String[]args){
int SizeArr = new Integer(JOptionPane.showInputDialog("Enter the size of teh array")).intValue();
int [] r= new int [SizeArr];
{for(int d=0; d<r.length; d++)
[Code]...
I am trying to create a class (DVD) with an instance variable that references a map, the constructor for this class must create an empty map and assign it to the instance variable map. I want to populate this map with instances of a different class called tv series, I am using blueJ, I am not sure why this doesn't work
Java Code:
import java.util.*;
public class DVD
{
public static Map<String, TvSeries>DVD;
public TvSeries program;
[Code] .....
I need a Java algorithm that converts a string of numbers into text. It is related to how a phone keypad works where pressing 2 three times creates the letter "c" or pressing 4 one time creates the letter "g". For example a string of numbers "44335557075557777" should decode where 0 equates to a space.
View Replies View RelatedSo I was just wondering if it's possible to create a program with JAVA that uses an algorithm to summarize data inputed. I've never done something like this before, If this is not possible with Java is it possible with C++ or any other language??
View Replies View Relatedwhat is mean by hash code??
View Replies View RelatedI want to generate a Hash key for a [ Nested Hierarchical nodes]. Any lightweight non-cryptographic hash map functions which generate a key, so that I can use this hashkey to comparison purposes.
NOTE: Security is not a concern for me, I just want to create a Unique ID.
LinkedHashSet=Linked + Hash +Set
In linkedHashSet are the elements stored according to the insertion order or according to the hash value. If the elements are stored according to the insertion order then why is it not named as LinkedSet instead of LinkedHashSet? Why is the word hash used in LinkedHashSet?
I am trying to add two strings to a hash map. the first being the key, a 3 digit code that can have duplicates, and the value to store in an ArrayList. From what I've read, when add a key to the hashmap that is a duplicate, the previous gets overwritten and that is why I am trying to put the values in an array list. I was hoping that when the key is looked up, it would print all the values associated with that key:
class library{
HashMap<String, ArrayList<String>> checkoutBooks =
new HashMap<String, ArrayList<String>>() ;
ArrayList<String> patName = new ArrayList<String>() ;
public void checkoutBook(String isbn, String patron) {
patName.add(patron) ;
[Code]...
So when I try to add values such as:
library.checkoutBook("000", "test 1");
library.checkoutBook("000", "test 2");
library.checkoutBook("001", "test 3");
library.checkoutBook("001", "test 4");
library.checkoutBook("002", "test 5");
library.checkoutBook("002", "test 6");
[Code]...
I am implementing the hash join algorithm for a project with a hard coded hash function. I've hashed the first relation and I've hashed the second relation. The problem is when hashing the second relation I only know how to add the tuple from the second relation into a third relation and not also access the first relation tuple at that time
The "hashtable" structure contains the hashcode of my key as well as the tuple stored in a string. This code below is taking place in the hashing of the second table, my function determines that both these tuples share the same hash code based on the first element in the tuple (element 0) so I add the tuple from my second relation to the qRelation but I also want to add the tuple from the hashtable at that point and I don't know how to access that string
if(hashtable.containsKey(tuple/*(RELATIONA)*/.get(0).hashCode()))
{
//Add the tuple from relation A into qRelation wich matches the
//above condition
qRelation.addAll(tuple/*(RELATIONB)*/);
}
I have a servlet that is not mapping to my URL:
<servlet-mapping>
<servlet-name>view</servlet-name>
<url-pattern>/View/*</url-pattern>
</servlet-mapping>
When I try to call the Servlet from a JSP:
<a href="/View/viewFlow?V1">V1</a>
The resulting link is [URL].... It's bypassing the project name. The link should be [URL]...
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter pw = response.getWriter();
String connectionURL = "jdbc:mysql://localhost:3306/userdb";// userdb is the database
Connection connection;
[Code] .....
When casting a char which is read from a file to an int, can i assume that the mapping used will be ASCII? I've learned that unicode uses ASCII mappings for the characters that overlap.
Are there any other possibilities for int values of one character? I still have trouble understanding character encodings.
I have to write a resize method so that when my Bucket gets to a certain point, then it resizes the bucket when it is called. What is happening is, I am getting strange results when I run the method. My mean bucket length should be at 2.5 for the last insertion, but I am getting something like 0.1346. Here is my dictionary class
// The "Dictionary" class.
// The Dictionary class implemented using hashing. Hash buckets are used. A dictionary contains a set of data elements with corresponding keys. Each element is inserted into the dictionary with a key. Later the key can be used to look up the element. Using the key, an element can be changed or it can be deleted from the dictionary. There is also an operation for checking to see if the dictionary is empty.
package dictionary;
public class Dictionary {
protected final static int MAX_BUCKETS = 1000; // number of buckets
protected DictHashEntry[] buckets; // the bucket array
private int collisionCount = 0;
[Code] .....
I have a drop-down which contains the four sections simple buttons(filters). When click any of these buttons some settings are applied. I have successfully auotmated it using simple if else and switch but in that case i have to use 8 parameters(8 are the number of button)
public void editFilters(WebElement filter1, WebElement filter2, WebElement filter3, WebElement filter4,WebElement filter5,WebElement filter6,WebElement filter7,WebElement filter8 String edit, String expectedColour) {
switch (edit) {
case "selectFilter":
if (filter1 != null) {
[Code] .....
But want to make it more effective by using hashes. I do not want to use 8 different parameters to perform action on the respective button.
So now what i want to implement.
Create a method in which i pass the parameter1 as hash and 2nd parameter as 0 or 1, 0 means unSelectFilter and 1 means select the filter.
With parameter 1, in code i want to pass the name or xpath or anything else for any number of filters , that those filters names should be stored into that hash and then by passing 0 or 1, i can select/unselect those filters.
I am trying to use this program for reference but its not working ...
View Replies View RelatedI am writing a program where I need to split an array of full names into First names and Surnames, using mapping. However, I am struggling how to split it up... and my First Names and Surnames list are both just displaying the full name.
public static void main(String[] args) {
String[] names;
names = new String[8];
Scanner s = new Scanner(System.in);
for (int i = 0; i < names.length; i++) {
System.out.println("Enter full student name:");
[Code] ....
I have this mapping:
<servlet>
<servlet-name>wsdl</servlet-name>
<jsp-file>/wsdl/bankconnect.html</jsp-file>
</servlet>
<servlet-mapping>
<servlet-name>wsdl</servlet-name>
<url-pattern>/wsdl</url-pattern>
</servlet-mapping>
And this works fine: URL....The war file is deployed under the context root /bankconnect/ I want to make a servlet mapping, before the context root "i still want the context root bankconnect". URL....
I'm working on a project and I'm just about to implement different stages (menus etc). The program is opened in an intro stage that just renders a text (slick, Unicode font) looking like this:
After switching to a different stage hat uses shadow mapping and then back to the intro stage it looks like this:
I've found that removing the line:
glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, 0, 0, shadowMapWidth, shadowMapHeight, 0);
solves the problem but then the shadow mapping isn't working.
I'm looking for a working example of shadow mapping with java code using shaders. There are so many c++ or c tutorials out there but i haven't managed to rewrite them since I'm too bad in c/c++. I've been trying to implement this a long time but can't get the hang of it. Any example out there? Preferably as sstripped down as possible except for the shadow mapping.
View Replies View RelatedWe need to process (read and parse) big xml files (500 Mo to 1 or 2 Go). What's the best framework or Java library to use for this requirement ? Then what's a good OXM (in this case xml to object mapping) solution for this kind of file ?
View Replies View RelatedWe generally use [URL] ..... for running web applications.
What I want is to access my web app using something like this: [URL] ....
How to achieve this? Actually what i want to ask is that how URL like WWW.example.com is mapped to web applications? Assuming that i am using tomcat server.
I have downloaded and testing these two mapping libraries. I wrote a program which has 100000 iterations and maps the beans of the same class:
public class IntBean {
@JMap
private int int1;
@JMap
private int int2;
[Code] ....
Mappers are created BEFORE iterations start:
private JMapper jmapper = new JMapper(IntBean.class, IntBean.class);
private MapperFactory orikaFactory = new DefaultMapperFactory.Builder().build();
private MapperFacade orikaFacade = null;
orikaFactory.registerClassMap(orikaFactory.classMap(IntBean.class,IntBean.class).byDefault().toClassMap()); orikaFacade = orikaFactory.getMapperFacade();
What is in each iteration:this.orikaFacade.map(a1, a2);
or
a2 = (A) this.jmapper2.getDestination(a1);
I know, that Orika and Jmapper are great libraries from Google and they use reflection in a different way than for example Dozer, which is much slower, they se reflection to generete code somehow..
I have 3 questions:
1) How they work - when the code is generated, during maven build, in runtime - everytime when I create mapper in code? Are they change class code byte dynamically?
2) Why there is this speed difference that I noticed?
3) Which library would you choose and why? Both have the same capabilities? Why both come from Google? Why Google didnt develop Orika and created Jmapper instead?