My GCD testing:
Java Code:
public static long gcd(long a, long b) {
if(b == 0) {
return a;
} else {
return gcd(b, a % b);
}
} mh_sh_highlight_all('java');
Is there a more efficient way? Also, what can I do to speed this forloop up?
Java Code:
for(long i = 1; i < 750000; i++) { dothis; } mh_sh_highlight_all('java');
I have this code which suppose to sort files by their length and return a string[] of th file names:
import java.io.File;
import java.util.ArrayList;
public class SizeOrder extends SuperOrder {
public String[] sortArray(File[] pathList) {
File[] absoluteOrderFiles = this.absoluteSort(pathList);
ArrayList<File> sizeOrderList = new ArrayList<File>();
[code]...
Now, in the following line: absoluteOrderFiles[absoluteIndex].length() < sizeOrderList.get(sizeIndex).length()
I need to use the compareTo which only exists in Long object.
How do I convert primitive long to Long?
and is it possible to do it in a single line?
my project flow is html,css,js<--->ajax<-->jsp<--->jdbc(.java)<--->mysql. In that jdbc i am returning the records from the database and fill into the resultset. From the resultset i put all records in arraylist and passed to jsp then i am displaying data in the screen.Whether i can use arraylist, hashmap or treetable?
View Replies View Relatedif one address point on another address. so set and get methods will be less efficient then an array, but add or remove will be more efficient by a linked list ? a linked list also inherit from queue so if i add an elemnt via "addFirst" function . where its adding the element ? to the right most or left most ?
if i have for example :
here [ ] --> [ ] --> [ ] --> [ ] -->[ ] or here
linked list its FIFO so the head will be the right most ?
Edit : its confused me a little bit but i understood now .so it will be at the left most. its actually ordered . not like the stack which is LIFO.
I've a question on rounding doubles on 0.05 As far as i know there is no class method that is able to do this. To achieve this rounding i have the following code:
Example:
164.67 -> 164.70
173.33 -> 173.35
0.02 -> 0.05
double calculatedQuantity = 0.0;
// Formula to calculate the average working hours in a month
int totalWeeksInYear = 52;
int totalMonthsInYear = 12;
[Code].....
I'm looking for a way to gather data from a site page. all data is shown in the same page... I am trying to get the content and parse it is a bit crazy as data seems to be not organized. Itried to get it as a document but still looks crazy.
As all data is shown very clearly in the page (I would like every row to be an object) I'm sure there is some way to collect this data easily. (the data is from this page: [URL] ....)
I'll attach a snapshot and the content I got from the website.
in-play.jpgall_in-play_page.txtin-play.jpgall_in-play_page.txt
I am kind of new to Java. I have a query.. look at it. Have an xml like
<ProductList>
<Product Quality='Good' color='Blue'>
<Details ItemID='1001'/>
</Product>
...
..
</ProductList>
The <Product> tags can run into hundreds or thousands. Quality can have values like Good, Bad, Damaged. Color can also have various values (Blue, Red ..)
ItemID can repeat or can be different. So I want group by ItemID->Color->Good count or BadCount and TotalCount as below.
I want to get a sum like
<ProductList>
<ProductType ItemID="1001">
<Product_Detail CountGood="1" CountBad="2" CountTotal="3" Type="Blue"/>
</ProductType>
...
...
</ProductList>
I think using Hashmaps (Hashmap1 for ItemID, Hashmap2 for color, Hashmap3 for quality) may do the work. But I have to parse the xml number of ItemID's multiply-by number of colors multiply by various colors times for this.
Any better algorithm is there in performance perspective using Java.
This isn't solely related to java.awt.Color, it's more of a question on how to store methods or redirections to use methods on any value passed in. To explain my question I'll describe a scenario:
ClassA is an instanstiatable class
ClassA has an instance of ClassB called cB
ClassA has methods of affecting cB
ClassD is also an instanstiatable class
ClassD has an Array[x][y] of instances of ClassA
I want to create a ClassE which I would initiate it with references to ClassA's methods or their actual methods and then I can use ClassE to easily transform ClassD's instances of ClassA by the same methods.
What I'm actually doing:
I made a class called GameColor, it has methods like changeHue, setRed, setHue, changeBrightness, setSaturation etc, these methods affect an instance of java.awt.Color in the GameColor class instances, so like they can change the hue or set it with changeHue or setHue etc...
Now I want to do something like perform a single method on a whole BufferedImage, on each of it's pixels RGB. So, I'm thinking of creating a GameColorEffects class which I store references or actual methods of GameColor like changeHue, and then I use GameColorEffects somehow to change a whole BufferedImage more efficiently, what's the most efficient way I can store methods or their reference of GameColor and then later apply them on each pixel of a BufferedImage using GameColorEffects. So all I do is initiate GameColorEffects with methods or reference from GameColor, and then I can apply it to easily transform each pixel.
with arrays its binary search which finds a value in O(Logn) time but what about linked lists ? the most effiecient algorithm will be O(n) ? and i know that binary search cannot be implement on a linked list , therefore , the only way to search a linked list is a linear search ?
View Replies View RelatedI have a maths application I am working on in java. This is more related to maths but there could be some here who have worked with calculations like this in their java project.
One could convert from degree to radians and from mph to knots. Could one convert from knots to degree or from mph to degree?
I am looking for a program to generate a unique alphanumerical identifier that is not too long; for example would start out with 6 digits like a licence plate or a postal code ex: AAA001 and use up all the possible combinations until 999ZZZ (just an example) and then when the possibilities are exhausted a 7th digit is added and so on. It matters not if they are sequential, the identifier just needs to be unique and not be too hard to remember (also i don't want to use ip adress or any personal identification). How I can accomplish this using java.
View Replies View Relateduse arrays to store taxpayer information. Use methods for tasks that will be repeated.
-Ask the user how many taxpayers he would like to calculate taxes for.
-Ask the user to enter each taxpayer's first name, last name gross income, and number of children.
-Each taxpayer's tax due is computed as follows
-The taxpayer's dependency exemption is determined by multiplying $3,000 times the number of children.
-The taxpayer's net income is determined by taking the taxpayer's gross income and subtracting the taxpayer's dependency exemption.
-If the taxpayer's net income is between 0 and 50,000, the tax due is 15% of net income.
-If the taxpayer's net income is greater than 50,000, the tax due is
-15% of the first 50,000 of net income PLUS
-25% of any income over 50,000
-The tax due can never be less than 0.
-If the net income is a negative number, the tax due is 0
TAXPAYER INFORMATION: output a message in one dialog box which lists the following info for every taxpayer: first name, last name, gross income, number of children, tax due.
AVERAGE TAX: output a message in a dialog box which states the average of the taxes due.
PRESIDENTAL MESSAGE: output a message in a dialog box which says either "We computed taxes for the president. " or "We did not compute taxes for the president." The president's name is Barack Obama.
Here is my code so far
import javax.swing.JOptionPane;
public class AssignmentSeven
{
public static void main (String [] args)
{
String [] taxPayers;
String[] firstName;
String [] lastName;
String message = "";
double[] grossIncome;
[code]....
I am facing problem during calculation in my awt calculator. It is showing NumberFormatException. Below is part of code.
if(e.getSource()==b14)//On button 14, label is "/"
{
String v1=tf.getText().toString();
num1=num1+Integer.parseInt(v1);//num1 is as integer variable
tf.setText("");//tf means textField
}else
[code]....
how to do this last calculation. I want the user to input and odometer (in feet) and have it use that and the Duration (in hours) to calculate speed in feet per second. Ive been trying to reference it using various methods but I'm stuck. I have it set as a string but whenever i try to pretty much use somewhat the same formula i did for total time it just gives me errors. How do I use that number the user inputs into a formula with the output of the Duration?
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package javaapplication1;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
[code]....
I am writing a program in Java where a user adds 1 stamp on a letter for every five sheets of paper in it (or fraction thereof)For example, I if I have 11 sheets of paper, I add 3 stamps. If the total number of stamps is more than 3, they don't send it.
I need to ask the user how many sheets of paper they have, and then calculate the appropriate number of stamps based on the formula above. I just don't know how to write the math formula to calculate this, i'm stuck. So far I have:
package test;
import java.util.Scanner;
public class LetterMailing {
public static void main(String[] args) {
Scanner stdIn = new Scanner(System.in);
int numSheets;
[Code] .....
What should I do next?
I'm trying to create a GUI interface in Netbeans that calculates a phone bill.
I created a GUI interface that input:
- Account Name.
- Account Number.
- Number of Minutes the phone was used. (with a textarea so the user input the minutes)
- 2 JRadioButtoms so the user can chose the regular or premium service.
- Amount Due (+10% taxes) (also with a textarea)
- Clear/Enter/Result/Done Buttoms
And I need to output:
- Account Name.
- Account Number.
- Number of Minutes.
- Taxes
- Total Amount Due.
I have a couple of math formulas I have to add them to output the above however I'm new to java so I don't know which code to use.
The math formulas are:
-Regular charges = 20 + ( No. Minutes - 50 ) * 0.20
-Premium charges = 50 + ( No. Minutes - 75 ) * 0.50
-Taxes = ( Regular charges + Premium charges ) * 0.10
-Amount Due = Regular charges + Premium charges + Taxes
I have about 100,000 (N) random long variables in an array. I'd like to find if any two longs are equal; they're not expected to be. At this size, should I use the Hashtable or brute force it at a cost of N^2/2?
View Replies View RelatedTaking two input strings that are integers such as "1234" and "567" then multiplying as you would do by hand. Trying to get them saved in the n3 new string but something is going wrong. You also need to account for the zeroes that have to be added just like on paper.
String mulN(String n1, String n2) {
int p = 0, tmp = 0; int zeros = 0;
String n3= "";
String r = "";
for(int i = n2.length()-1; i >= 0; i--) {
[Code] .....
I'm trying to write a condition to jstl if tag,
<c:forEach var="ledg" items="user_ledgers">
<c:if test="${ledg.transactionID == param['trns']}">
<c:out value="${ledg.name}"/>
</c:if>
</c:forEach>
Ledg is an object of ledger class and transactionID is a field of type long.
I found this error while runtime.
javax.el.PropertyNotFoundException: Property 'transactionID' not found on type java.lang.String
I tried to convert transactioID value to String by several ways. But not working.
String concatenation
<c:if test="${(ledg.transactionID+’’) == param['trns']}">
Using custom tag
<c:set var="equals" scope="page">
<z:doTheyEquals v1="${ledg.transactionID}" v2="${param['trns']}"/>
</c:set>
It also expects String type.
Java Code:
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class PrintALongFile{
public static void main(String[] args) throws FileNotFoundException{
File inFile = new File("C:VeryLongFile.txt");
[Code] .....
When I try to read from a file that's 4,075,904 lines long and 41,646KB in size, it wont go past line 1,266,471. The above code is simplified from my actual program, which actually prints out the results to another file. However, the console (Eclipse IDE) and the output file, both show that it's stopping at the same line.
How can I read the to the very end of my file?
How can I store a value in long type variable whose range is greater than int type variable ....
View Replies View RelatedI have a calculation that sorts books by rating...
System.out.println("
" + "
Sorted by Rating
");
for (int count = 0; count < bookL.size(); count++) {
for (int in = 0; in < bookList.size() - 1; in++)
if (videoList.get(in).getRating() < bookList.get(in + 1).getRating()) {
[Code] ....
What am I missing here? Why doesn't this work?
As stated in the subject I'm a newbie when it comes to Java Programming (I'm in my second week of class). I'm trying to create a Retail Calculator for a class and need to multiply two values together (Price, Discount) in order to get the sale's price when the user hits a Calculate button. The price and discount are user input values from textfields in the beginning of the code.
public void actionPerformed(ActionEvent e) {
String price;
String discount;
float salePrice;
//Get the original price from price textfield
price = priceValueField.getText();
[Code] ....
This may be a multipart question. Basically I have to write a program that accepts a string, converts it to a double splits it and then performs a calculation.
public static void main(String[] args) {
String input = ""; // initalize the string
boolean isOn = true; // used for the while loop...when false, the program will exit.
String exitCommand = "Exit"; // exit command
String[] token = input.split(("(?<=[-+*/])|(?=[-+*/])"));
[Code] ....
This is the error I get:
Enter a math problemException in thread "main" java.lang.NumberFormatException: empty String
at sun.misc.FloatingDecimal.readJavaFormatString(Floa tingDecimal.java:1842)
at sun.misc.FloatingDecimal.parseDouble(FloatingDecim al.java:110)
at java.lang.Double.parseDouble(Double.java:538)
at Calculator.main(Calculator.java:22)
[Code] .....
How do I go about actually fixing it. Without that line commented out I get this:
Enter a math problem
2+2 <-What I entered
[Ljava.lang.String;@135fbaa4
Also, how would I go about using the submethods to check for valid operands and operators (also part of the problem) I have the actual lists made obviously, but am unsure how to get those to work with the problem.
I have to use a long primitive type for the input of a credit card number and ID the credit card by using the first number of the input; however, the only way I know for that is to use charAt, which is used for a String. Is there a way to convert long to String, or am I missing a better solution? (There's no code because I'm still doing the pseudocode).
View Replies View RelatedI am new to programming, but am working on a program that takes 6 inputted grade averages on a scale of 0.0 - 100.0 (exceptions in the case someone has exceeded the traditional 100.0 limit) and then divides it by 6 and returns the value in a dialog box. However, I want to take the values inputted and convert them to a 4.0 scale (90.0-100.0 = 4.0, 80.0-89.99 = 3.0, etc.) and then get the average of that so that I can return an average on a 4.0 scale. I have been trying to accomplish. Also, as of right now my program only prompts the user for 6 inputs, but I'd like the user to be able to input as many as he/she would like to, I am pasting the code I currently have below.
import javax.swing.JOptionPane;
public class GPA_Calculation1_0 {
public static void main(String[] args) {
String courseOne = JOptionPane.showInputDialog("Enter numeric GPA of Course One: ");//Course one
double numOne = Double.parseDouble(courseOne);
[Code] ....