Double Hashing For Inserting Integer Into Hashtable
Apr 26, 2014
I'm having a problem with double hashing, its supposed to have the user insert an integer into the table and the integer is hashed into the table by the mod of the size of the table so say for instance table size 10 I insert 89 that inserts into 9 because 89%10=9 then i insert 18 that goes into 8 but then once i insert 69 its supposed to collide with index 9 and then uses 7-(69%7) for prime number double hashing...but it just goes into index 9 instead so in 9 it puts 89,69...there's no errors just the wrong output
System.out.print("Enter size of table: ");
int n = input.nextInt();
size=n;
a = new ArrayList[size];
for (int i = 0; i < size; i++) {
a[i] = new ArrayList<Integer>();
I'm having a problem implementing double hashing when I insert a value into the table i get this for the output:
Insert []. Is there something I'm doing wrong? I'm not getting any errors
public static int size = 0; public static ArrayList<Integer>[] a; public static void interactiveMode(Scanner input) { int menuChoice = 0; do { System.out.println(" Interactive Mode:");
I am having some problems with some code and I need an extra set of eyes. It appears I've missed something. I am getting a NullPointerException with a Hashtable object, which I can clearly see I've created. So I'm not quite sure why it is happening. I am pretty sure it is do with the code I've posted because I've tested everything else involved.Here is the code where it happens,
I was browsing around and I found a question asking to find how many times a word occurred in a sentence. I am using a hashtable, over kill yes but I need to use them more. However my counter is not working, not really sure why.You can see in the main method I have two repeating names but it returns 0.
package frequency; import java.util.Hashtable; public class CheckFrequency { hashtable<String, Word> words = new Hashtable<String, Word>();
I am having some difficulty adding a new item to the HashTable when a collision occurs. We can only use the basic utilities to code this, so we are coding a HashTable by hand. We have an array of length of 10, which each index holds or will hold a Node for a Linked List.
The code hashes fine, adds the item, but the problem exists when adding items that already been hashed. The project is much bigger, but this is the engine behind the rest, and I figured I would tackle this first.
The items we are adding are objects which are states containing different information, we hash based on the ASCII sum % tableSize.
Here is the code I am testing with to add items:
HashTable ht = new HashTable(10); State az = new State("Arizona","AZ","W",2,"Y",2); State fl = new State("Florida", "FL", "F", 2, "X", 2); State hi = new State("Hawaii", "HI", "H", 3, "Z", 1); State al = new State("Alabama", "AL", "A", 5, "W", 0); ht.insert(hi);
I'm writing the remove method, where you insert the key and it searches the key, if the key is found you remove the value inside the table and return that value, if they key is not found you return null. I did this method but is not returning anything in the main so I try to print inside an if to see if it was entering the condition and it appears to be looping, I'm using arrays because its an assignment
public V remove(K k) { int key = funcionHash(k); V key2 = (V) tabla[key].value; int intento=1; if(this.estatus[key]==1){ while(intento<this.tabla.length/2){ if(this.tabla[key].key.equals(k)){
I need to implement a separate-chaining hash table from scratch and I don't need to know the code or anything I would just like an explanation of how I would go about doing the algorithm for this perhaps pseudocode and then I can figure out the rest.
How can I write a BufferredImage to an 8-bit .bmp using indexed colors stored in a <String,Color> Hashtable?
I've never used Hashtables before, and I didn't know color indexing existed until now, but I can do most other things in java fairly well.
I'm not looking for code, just the concept, as I really don't know how Hashtables work (although I could figure it out), and how color indexing does. I know how to write image files, just not indexed or with a specific number of bits. I am using Hashtables generated from GIMP.
EDIT: I mainly want to know how to save a BufferedImage as an indexed .bmp.
I have a jsp page that generate a hashtable and display its key-value pairs back to the browser. The problem is that it takes on an average about 15 minutes to build this hashtable, and as a result, I always get a timeout error. What can I do to avoid getting the timeout error without changing the server configuration for timeout
public class MyInteger { private int value; public MyInteger(int number){ value = number; System.out.println("Constructor created with value of " + value);
[code]....
I can't seem to get the value for integer1 and integer2 to pass with the setValue method. I get a runtime error stating the I need to have an int value for these two integers.
having trouble trying to understand the insertion and removal of Nodes.
I have to insert a new node at the end of the linked nodes, if i insert by terminal : 1, 2, 3. The printed nodes are going to be in the same order, 1,2, 3.
I have done the exercise, but it only prints the last node created and i dont know where its the problem. We did it before with "insert at the beginning", may be the problem is with the print() method in SimpleList.java, but i dont know how to print "backwards".
This is the code:
Node.java
public class Node { public int infoNodo; public Node next; } SimpleList.java public class SimpleList { private Node head;
I know the below code is supposed to format the FormattedTextField but it doesn't seem to do anything to the form (shown in the picture below). I was wanting, when the form loaded: the text field to look something like this
00/00/2014 - 00:00 am
Where the user is able to
- enter datelike information around the symbol separators ( / or : )
- But where the user could not remove these symbol separators
Code:
package datefield; import javax.swing.JFormattedTextField; import javax.swing.text.DateFormatter; public class NewJFrame extends javax.swing.JFrame { public NewJFrame() { initComponents();
What I'm supposed to do is make a method to insert a set of Tiles to the list,i.e.,a detour(make sure that the inserted detouris compatible with thecurrent path so that the resultingpathdoesnot have any gaps). But I'm confused on how to go about doing it. I was thinking of maybe just adding 1 to the current Node.
import java.io.File; import java.io.FileNotFoundException; import java.util.List; import java.util.Scanner; public class Path { static Tile startTile;
So I'm doing a project for my CS class where we have to create a snowman doing something. My picture is of Vince Young in the 2005 Rose Bowl. I'm trying to make the actual video clip from Youtube (do I need to download it? If so I can do that) appear on the scoreboard, but how.
import java.awt.*; import java.awt.event.*; import java.awt.Font.*; class snowBackground { public static void drawField(Graphics g, Color field)
[code]....
There are 3 other files that make the actual Snowmen.Also, would I need to download the mp3 sound file seperately and play that, or will inserting the video do both?
So I'm doing a project for my CS class where we have to create a snowman doing something. My picture is of Vince Young in the 2005 Rose Bowl. I'm trying to make the actual video clip from Youtube (do I need to download it? If so I can do that) appear on the scoreboard. As of right now, this is my background file:
import java.awt.*; import java.awt.event.*; import java.awt.Font.*; class snowBackground { public static void drawField(Graphics g, Color field) { Color sky = new Color(95,166,243);
[Code]...
and this is the Driver file (not sure if this is necessary):
import java.awt.*; import java.awt.event.*; import java.awt.Font.*; public class SnowDriverWSB { public static void main(String args[]) { GfxApp gfx = new GfxApp(); gfx.setSize(1000,650);
[Code]...
There are 3 other files that make the actual Snowmen. To do this, I need VERY basic steps, as I'm extremely confused and new to Java. Also, would I need to download the mp3 sound file seperately and play that, or will inserting the video do both?
I know that for a binary search tree the insert() method is easy. You just kept comparing the values of the nodes, and you would know whether to go left or right depending on the value of the node.However, I am stumped when trying to figure out how to add a node into a normal binary tree where you just keep adding the nodes to the leftmost side, regardless of value.Here is my attempt at the insert() method:
public class RegularTree extends BinaryTree { public CompleteTree() { super(); }
public void insert(Comparable item) { if(this.isEmpty()) { this.setRoot(new TreeNode(item)); return;
So I am working on a DB homework assignment and I am confused in how to implement a users input into the DB; I have to enter some values into a Table that is filled out by a user. It is a basic program, no GUI needed at this point.
I have written the main part but I don't know how I would get the typed value of the data into the SQL Insert Query.
Here is my code (I have a working Database and table with Java DB)
public class AddPeople { public static void main(String[] args)throws Exception { Scanner kb = new Scanner(System.in); try { Connection conn = DriverManager.getConnection("jdbc:derby:PeopleDB");
I know the below code is supposed to format the FormattedTextField but it doesn't seem to do anything to the form (shown in the picture below). I was wanting, when the form loaded: the text field to look something like this
00/00/2014 - 00:00 am
Where the user is able to
- enter datelike information around the symbol separators ( / or : ) - But where the user could not remove these symbol separators
I am very new to threading. I have a program that calls my api and gets data back in json format. Each request returns a row of data in json format. All together I need to retrieve about 2,000,000 rows a day which means 2,000,000 requests (I understand that this is bad design, but the system was not designed for this purpose it is just what I need to do for the next couple of weeks). When I tried running it on a single thread I was processing about 200 requests a minute which is much too slow. As a result I created 12 threads and I was processing 5500 rows a minutes which was a great improvement.
The problem was only about on average 90% of the rows were inserted into the database as I ran it a few times to make sure. Before each insert printed to a file each URL which was sent and then I checked to see if each insert statement was successful (returned 1 when executed ) and it all seems fine. Every time I run it it inserts about 90% but it does varies and it has never been a consistent number.
Essentially the code starts in main by creating 12 threads. Each thread's creates a run method which calls a new instance of MySQLPopulateHistData and passes a start and end integer which are used in the insert statement for ranges. I have done many system.out.println type testing and can see all the threads do start and all the 12 instances (one instance for each thread) called are executing?
MAIN:
import java.io.IOException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; public class MainClass { public static void main(String[] args) {
I'm using this try statement to check for errors in input in my Tic Tac Toe game. The problem I have having is I don't understand why this error is happening. It's preventing my code from compiling. I've tried inserting an else statement and multiple brackets at various places with no success.
Java Code: public void play(){ Scanner input = new Scanner(System.in); int row, col; char currPlayer = 'X';
