Program With Hashset
Dec 10, 2014
A file has the data of the subjects and name of professors. The file contains line for each subject. The line starts with professor Name followed by the Subject name.
Harry Williams Advanced DBMS
James H Computer Networks
Sasha Ben Artificial Intelligence
Harry Williams Software Engineering
Palbo Kastro Formal Languages
Alex W Advanced SE
James H Operating System
Harry Williams Theoretical Foundation
Write a program with setter getter method to read the file, and then write a class to store several professors in a hashset (Single Key and Multiple Values).The program should be able to display all the professors in the set and allow the user to search for a professor.
Input:
Professor Name: James H.
Then the Output will be:
Subjects Taken by the professor: Computer Networks, Operating System.Display No Classes available if the professor name does not exists .
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Mar 23, 2015
I am trying to write a hashset to a text file. Normally, I have no issues with writing to txt as it is simple for me. However, in this case I am absolutely clueless.
A bit of background about the class: it is a hashset of ComputerScientist objects with 2 fields; name, and field of research (and yes, I know what I put to fill up the HashSet does not count, I was only trying to test to see if I could get this to work).
I know the basic setup to use filewriter to save strings to a txt, but I am getting confused with the HashSet element of it.
import java.util.HashSet;
import java.io.FileWriter;
import java.io.IOException;
/**
* Write a description of class ComputerScientistSet here.
*/
public class ComputerScientistSet {
private HashSet<ComputerScientist> computerScientistSet;
[Code] .....
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Nov 18, 2014
Having trouble adding Class (Dollar) objects to a HashSet (money), i have done this before with arraylists and i understand that HashSets are different in that they cannot contain duplicates. Currently when this code is compiled i am getting "null" printed when I run the "howFullDatWallet" method.
import java.util.*;
public class Wallet {
private HashSet<Dollar> money;
private int walletSize = 0;
private int walletFiller = 0;
/**
* Constructor for objects of class Pocket
*/
public Pocket(int walletCap)
[code]....
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Apr 20, 2014
I have a HashSet, which I created to prevent duplicates upon output, but of course it's printing duplicates(or else I wouldn't be posting this). The order of my output does not matter, nor the input. The data type is String in the format (x + "," + z), where x and z are integers, creating a collection of coordinate sets. So to prevent the output of duplicates, I'm trying to get rid of the duplicates before they are added to the collection.
I've tried doing a '.equals()' string comparison but what happens is, since my string is added via one variable, it compares itself to itself and if itself equals itself it won't be added to the collection. I really need to keep this as a comparison of a single variable, because creating a key for each value would be sooo ridiculous for this volume of inputs.
So, with that being said, I would like to add one copy of the string, discard the duplicates, and do this thousands of times..
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Mar 12, 2014
What is the difference between HashSet, TreeSet and LinkedHashSet?.One difference between HashSet and TreeSet is that TreeSet is sorted, whereas HashSet is not sorted. I dont know the other differences
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Apr 3, 2015
I'm fairly new to java, and is just building small programs to get the feel for the language. How I can improve this code.
import java.util.Set;
import java.util.HashSet;
import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
enum DateValidator {
DDMMYYYY(0, 2, 4),
MMDDYYYY(2, 0, 4),
YYYYMMDD(6, 4, 0);
[Code] ....
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Jan 12, 2015
Is there any way to find how many number of elements are landing in same bucket in HashSet. I know Reflection could be one way but i am not able to design a program for that.
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Sep 23, 2014
I'm not new to java but i'm not able to solve the following issue: I have a class
public class Localizzazioni implements java.io.Serializable {
private <complexType> id;
public getId().......
public setId().....
The complexType is a class defined in the code somewhere. Now I want to access it in another class I have
Set localizzazioni = new HashSet(0);
localizzazioni=opere.getOiLocalizzazioneOperas(); -- this object give an object of tyoe HashSet
for(Object object : localizzazioni) {
object.get......... // i cannot use any method defined in the class Localizzazioni
}
Why I cannot write inside the for object.getId() and using it?? In other word how i can access the element contained in the object?? the object is an iterator of type Localizzazioni . The class Localizzazioni has some method but i cannot use them? why ....
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Sep 13, 2014
I have two Strings
String TO = "raj@gmail.com;ra@gmail.com;RS@yahoo.com";
String CC= "rajt@in.com;rht@basss.com";
My query is i want to extract domains from above two Strings and Store these domains in HashSet. How could i do this with minimum code and performance wise.
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Mar 16, 2014
i want create little program which enter the number, ant program says triangle exist or not. So code :
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
[code]...
So when i put first num like 1, next num like 2 and next num like 100 , program says Triangle exist.
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Apr 16, 2014
Have written a program to open Excel sheet from java program.Below line works fine.
Process p = Runtime.getRuntime().exec(new String[]{""C:Program Files (x86)Microsoft OfficeOffice12Excel.EXE"","C:UsersRASHPA~ 1.ORAAppDataLocalTempExport_xl420314062726 9379706.xls"});
But below code gives error i.e. Executable name has embedded quote, split the arguments
String path = "C:Program Files (x86)Microsoft OfficeOffice12Excel.EXE";
String file = "C:UsersRASHPA~1.ORAAppDataLocalTempEx port_xl4203140627269379706.xls";
Process p = Runtime.getRuntime().exec(new String[]{"""+path+""" + ","+file});
I am using java 1.6.
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Dec 17, 2014
In a project for school. I have a program that links several GUI's as a menu based program. What I am trying to accomplish is when one of the previous GUI's is closed that it doesn't terminate the entire program. There is a lot of classes in the entire project so I'd prefer not to paste all the code here, but if it is necessary I will do so.
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Feb 20, 2014
I'm creating a program that will compile and run another java program:Lets say I have a program in directory
D:HelloWorldsrc
and compiled program will be in
D:HelloWorldin
inside src and bin is a folder hello (that's a package)
package hello;
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World");
System.out.println("Hello World");
}
}
This program will be run by another program (that's the program that I am creating).Here is the code of my program:
package runnercompiler;
import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
public final class RunnerCompiler {
[code]....
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Feb 15, 2014
I'm working in a GUI program, but I'm not going to put the code because there is a lot of code and files. Instead, I will try to put it an example.
Let say:
I'm working in a GUI program that ask form the user to enter two number's. When the user press at the calculate button. It will show up the output. However, the program won't exit unless the user press at red (X).
int x = user_Input1;
int y = user_Input2;
int total = x + y; //
JOptionPane.showMessageDialog(null, total);
I know that there will be a (total) now, so my question is here how can I reset all the calculation and have a new total that will show up when the user enter two number's again.
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Jun 18, 2014
I have searched the internet for about 2 days and now i'm posting this. I'm trying to make a program that will let me enter "1" to show how many movies I have watched and press "2" for a new one. The problem I ran into is I enter 2 then when I enter 1 it said "you have watched 0 movies". I know what the problem is I just don't know how to retype it. here is the code.
package stuff;
import java.util.*;
public class thing {
[Code].....
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Dec 14, 2014
I just finished a tutorial on youtube that covers the basic java, and now i want to try and make a game / program thing, only problem is that i have never worked with graphics before (i have tried to make ovals, rectangles, and other things with the paint method tho )
I know how to make a jframe and a jpanel, and i feel like i can make a simple "game" (not a complicated one, just a simple one with a guy walking around on the screen) in fact i have already make a such game, where you are a oval walking around on the screen, so thats not really my problem.
My problem is that i want to draw an image on the screen that can walk around instead of the oval, but how to do that. I have made a new project and set up the jframe and jpanel, and my code looks like this:
(main)
import javax.swing.JFrame;
public class main_class {
public static void main(String[] args){
JFrame f = new JFrame();
f.setTitle("title");
f.setVisible(true);
f.setSize(800,600);
[code]...
but once again, i get a blank jframe with no image and no "test" string . How i can display images on the screen?
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Feb 7, 2015
I have done a rock, paper, scissors program, but it only executes once. How do I make the program repeat so you can play multiple times?
import java.util.Scanner;
import java.util.Random;
public class RockPaperScissors {
public static void main(String[] args) {
int A;
Scanner input = new Scanner(System.in);
Random random = new Random();
[code]....
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Mar 25, 2014
I am new on this and I will be working in a gpa and average program. This is my code so far: Every time that I try to add the gpa part it gives me errors or just duplicates whatever I've in average and displays it in gpa
/**
* This program shows a database of students in a school.
* It gathers information as name, classes, grades, and calculates average and gpa average.
*
*/
import javax.swing.JOptionPane;
[code]....
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Oct 15, 2014
In this exercise you will write a program that estimates the value of π. Pretend that we are looking at a dartboard in the picture above. If the square is 2units wide and 2 units high, the radius of the circle within the square is 1 unit. Then the area of the circle is π*r2 = π*12 = π. The area of the square will be 2*2 = 4.
The estimation of π will work by randomly "throwing darts" at the dartboard. We will assume that every dart will hit the board but the location of that strike will be random so some darts will land inside the circle and some will land outside the circle. The calculation of π is then the ratio of the number of darts that land inside the circle to the total number of darts, multiplied by 4. Note that as we increase the number of darts used in the simulation, the accuracy improves.
Follow the steps to complete the program:
1.Declare variables that represent x, y coordinates of a dart, the distance of the dart from the origin, the number of darts that land inside the circle, and the total number of darts.
2.Read in the total number of darts (N) from the user and create an instance of the Random class.
3.Create a loop that runs N times. Inside the loop, you will use the nextFloat() method of the Random class to create x, y coordinates randomly, and then compute the distance of the dart from the origin. Determine whether the dart lands inside or outside of the circle.
4.Compute π using the estimation algorithm.
5.Run the program with increasing numbers from 100 to 100,000,000 and observe the accuracy of π.
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Mar 24, 2014
So the question asks us to use a sentinel value to end a program, but the sentinel value is 999, but the while loop only recognises strings...
static Scanner console = new Scanner (System.in);
public static void main (String[] args)
throws FileNotFoundException
{
PrintWriter outfFile = new PrintWriter ("Invoice.txt") ;
String firstItem;
String item ;
int price;
[Code] .....
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Aug 22, 2014
This program will compile. Yet once i run it it immediately terminates itself....
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
public class myImageIcon extends JFrame{
[Code] .....
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Jan 15, 2015
The objective of the program: Write a method that takes a string as input and returns the letters contained in that string in sorted order as output. For example, an input of "Computer Science" would print the following as output (case is ignored): ccceeeimnoprstuthe code works otherwise
import java.util.Scanner;
public class weeklyProblem4 {
public static void main(String[] args) {
Scanner console = new Scanner (System.in);
System.out.println("This program takes a string as input and returns the letters contained in that string in sorted order as output");
System.out.println();
System.out.println("Enter some string");
String userstring = console.nextLine();
sortedString(userstring);
[code]....
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Oct 21, 2014
how to put search bar in my program.i am just new to java programming so i dont really master all the codes.i dont have much time
import java.io.*;
import java.util.Scanner;
public class myjavProject{
public static void main(String[] args)throws IOException{
PrintWriter output = null;
String ID;
String firstname;
String lastname;
String ans = "y";
String userinput;
[code]....
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Sep 4, 2014
I am new to programming and this is my first assignment. A sample of the final output is:
-"How many digits would you like to compute Pi to?" 2
-"It took 200 terms to approximate Pi as 3.136592684838816"
What I have so far, ask the user for input then stops!
import java.util.Scanner;
public class PiApproximation
{
public static void main(String[] args)
[code]...
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Mar 7, 2015
I have to create a class that asks the user to answer a multiplication problem. It randomly pulls to integers. If the answer is correct it displays a response if its wrong it displays a response and tells them to try again. at the end it displays all the questions with the answers. For some reason when i run the program it automatically terminates but doesnt give me an error.
Java Code:
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;
//import javax.swing.*;
public class StudentMath {
[code]....
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Apr 9, 2014
use 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]....
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