I have a list of 100,000 + names and I need to append to that list another 100,000 names. Each name must be unique. Currently I iterate through the entire list to be sure the name does not exist. As you can imagine this is very slow. I am new to Java and I am maintaining a 15+ year old product. Is there a better way to check for an existing name?
View RepliesSuppose i have given a List<Intervals> list; I am iterating over list and inserting each element from list into BST, if time require to insert into BST is logn then what is the total time require to insert all the elements into tree ?
logn or nlogn ?
I'm trying to use the DataFactory class to pull in a list of names, as I need to populate my app in development with randomized test data for testing.
DataFactory
So, I can get a random name like so:-
package domainentities;
import java.util.Random;
import java.util.Collections;
import org.fluttercode.datafactory.AddressDataValues;
[Code] .....
But - it always prints 'Lindsey'. I need a way of completely randomizing but I can't see the class has a method to let me do this? I can use the randomize method but this takes an int argument which will always bring back the same index value (same name).
I wonder if I am over complicating this. I can use a simple String array of names, but I don't want, like 10,000 names in my array and I want a good way of generating good, randomized data. Perhaps a .csv file of names could be read in? Here is a second method I wrote but I don't have the skills to know how to read the array values from my large .csv file:
public String randomSecondName(){
String[] lastNames = {"Smith", "Jones", "Collins","Jackson",
"Dearsley", "Trump", "Carr", "O'Connell", "Dyer", "Furstzwangler" };
Random ran = new Random();
String lastName = lastNames[ran.nextInt(lastNames.length)];
return lastName;
}
One of my assignments was to make a program that would read a sequence of names and then list them all.Just to be clear, it would read them all first, and then it would list them all at the same time.
View Replies View RelatedAn array which contain a list of names. I let for a user input and I use that to search through the array. For example lets say the string name "Christian" is stored inside the names array and the user types in Chri, the program looks in the array and finds a name that contains Chri and prints them out. How do I go about doing this?
View Replies View RelatedI am trying to write a java program that asks the user for a list of names (one per line) until the user enters a blank line. At that point the program should print out the list of names entered, where each name is listed only once (i.e., uniquely) no matter how many times the user entered the name in the program. I am supposed to use an ArrayList for this problem.
My idea for a solution is to create an ArrayList<String>, read each name, i.e., line, entered and then to see if that name is already in the ArrayList. I created a for loop to check each element in the ArrayList but when I try to assign an element to a string variable I get the error "Type mismatch: cannot convert from Object to String". Not sure why that is happening because the ArrayList is defined as a String list.
Here is the code so far.
/*
* File: UniqueNames.java
*/
import acm.program.*;
import java.util.*;
[Code].....
a project I am working on. Its a program that creates a singly linked list that stores names and high scores and prints them. For some reason it is printing an entry extra times. Also my remove function is not working properly
GameEntry class:
package project;
public class GameEntry implements Comparable<GameEntry> {
private String name;
private int score;
public GameEntry(String n, int s) {
name = n;
[Code]...
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 table UI and want it to be to be in sync with tabledata in the database... How can i go about it?
View Replies View RelatedI have some class called sorted to sort the linked list through the nodes of the list. and other class to test this ability, i made object of the sort class called "list1" and insert the values to the linked list.
If i make other object called "list2" and want to merge those two lists by using method merge in sort class. And wrote code of
list1.merge(list2);
How can the merge method in sort class know the values of list1 that called it as this object is created in other class.
I receive a java.lang.NumberFormatException: For input string: ""DepDelayMinutes"" error when trying to filter a list and then assign the results to a new list.
I have edited the code so it is an int that throws the exception so it isn't the presence of a string that is causing the error - java.lang.NumberFormatException: For input string: ""0914"" .
I believe the issue is because of the two sets of double quotes but I do not understand how they came about. The original dataset does not have any quotes whatsoever.
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.function.Predicate;
import java.util.stream.Collectors;
public class FilterObjects extends Thread{
[Code]...
So we have an assignment regarding a linked list implementation of a given list interface.
In my list interface, the method contains(T anEntry) is defined.
In the LList implementation, contains is already implemented as part of getting the core methods in.
Now I am being tasked with the following:
Provide a second implementation of the method contains2(T anEntry) that calls a private recursive method
Private boolean contains (T anEntry, Node startNode) that returns whether the list that starts at startNode contains the entry anEntry.
I've written the private recursive method already. That's not an issue (at least not right now).
But what I don't understand is how startNode is supposed to be populated when this private contains method is called from the public contains2 method? contains2 only takes one parameter: anEntry. the private method takes two parameters: anEntry and startNode. How am i supposed to provide startNode when I am calling contains2?
I saved the content of an ArrayList<SomeClass> to a file
I write each serialised object to the file by adding to each an id that is created with list.indexOf(object) (and saved before each object)
So I can repopulated the list with SomeClass objects in the same order as they were and once I reload the file, I do list.add(id,object)...
Well my list is populated upside down, I mean the first object is the last and the other way around, If i remove the id when I do the add(object)...
I have this ListInterface class that has operations for my linked list and a LList class. The Llist and ListInterface classes are perfect. My job is to create a driver, or a demo class that showcases these operations. That being said, heres the driver so far:
import java.util.*;
public abstract class DriverWilson implements ListInterface
{
public static void main(String[] args)
{
LList a = new LList();
[code]....
public void add(int d){
listNode l = new listNode (d, null);
l.next = first;
first= l;
}
public list Sum2List (list l1, list l2){
//variables
int sum;
[Code] .....
But I have a problem in my first listNode where it ll be pointing to null, thus in the sum2List method the program checks the while condition into false and doesn't go through the loop.
I am creating a program called "Mad Math Machine". This program is to generate random arithmetic questions, with integers ranging from -12 to 12, for the user to answer. The user has three lives. Once they get more than three questions wrong, they run out of lives, and their "score" (the number of questions they answered correctly) is taken.
I have the large chunk of the program (the arithmetic questions and answers) completed. The only part I am stuck on is the scoring system. I believe that arrays would be useful for this task, but I have little idea of where to start. Here is what the scoring list should be able to do:
- It should print out the top ten recent players and their scores.
- A separate list should show the top-two highest scores of all time.
*I didn't think it was relevant, but I can include the program code. Up until this point, I have created methods to keep track of the score, but I have simply left them commented out so I could build the rest of the program.*
I have arraylist which is already set in controller side.
I need to update the same list(removing few elements in the list) in jsp based on few conditions like, the selected values in dropdown kind off.
How to update the list in jsp?. Is there any way to handle this using JSTL?.
Instead of using scriptlets, can i do this?
I first learned how to program with BYOB. In BYOB there were variables and lists. Variables worked the same as Java and lists were groups of variables. To create a list, I would give it a name. I could then add variables to this list as items throughout the program. Here's an example of what a list would look like:
[[List]]
item 1: Hello
item 2: world
I could then call upon item 1 or item 2 and delete them if needed. In Java, I want to have 3 lists of variables into which I put user input as variables. The code would look something like the following: (stuff with "//" at the end is detailing what I want to do, not actual working code)
import java.util.*;
public class Archives {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
[code]....
How do you format an arraylist?
Mine looks like this:
[<?xml version="1.0" encoding="UTF-8" standalone="no"?> <DefEnv id="Dev">, <Envt id="Test">, , <DB id="DM">,
But I want it to look like: I'd prefer if the '[' , '<>' and ',' were not on them also but I'm not too bothered about that bit.
[<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<DefEnv id="Dev">,
<Envt id="Test">, ,
<DB id="DM">, ]
Add accounts on a list, each account contain: name, accountCode, pinCode, balance.
How to show list sort by balance?
I want to create a quiz in java in which questions and options will be retrieved from mysql database.I want the options to be in drop down list format.And I am using jsp for presentation layer and all the connections with database are in java..how to retrieve the options from database to drop down menu...
View Replies View RelatedI have figured out, how to diplay basic datatypes of an entity / object in a dataTable, but I can't find a way to display a List<String>.
I also tried it with ui:repeat, but the space, where it should appear, stays empty. This is my code right now:
Product.java (the entity)
...
@ElementCollection
@CollectionTable(name="NeededRessources", joinColumns=@JoinColumn(name="product_id"))
@Column(name="resource")
private List<String> neededResources;
...
And the page: index.xhtml
<ui:repeat value="#{product.neededResources}" var="t">
#{t}
</ui:repeat>
I need to choose the value of a list item in jsp. There are many employees in various departments and i need to choose that employees in department wise.
Example. I have two list items in jsp
1. Select dept_no,dept_name from departments
2. SElect emp_name from employees, departments where emp_dept_no=curr_dept_no and curr_dept_no = dept_no
These two are the list items. When i choose the department from the first list item i need to display the employees in that particular department in the second list.
I have a HashMap with multiple values at runtime. In that map one key has empty value , how to avoid this value to add in a list. some code sample is below:
public HashMap getLoop2Map(Map map, String xslFile , int sheetNo){
HashMap hashMap = new HashMap();
try{
ArrayList list = new ArrayList();
System.out.println("-------Map : " +map);
list.add(map.values());
//System.out.println("------- boolean : " +val);
System.out.println("------List : " +list);
}
I do not want to add the empty value in a list ...
result in map
-------Map : {Free Text Entry={},
Mouth / Throat={Free Text Entry={Free Text Entry=<FORMFILENAME>EditChartPhysicalExamText.form
</FORMFILENAME><TAG>"<MUSCULOSKELETAL.PE>"</TAG>},
Salivary Glands Condition={Salivary Glands Condition=MouthAttribute},
Examination Overview- Mouth / Throat={Examination Overview- Mouth / Throat=MouthAttribute},
Tonsils={Tonsils=MouthAttribute},
[Code] ....
I want a list of all running application in my java code.I got list of all the running processes by my code but I dont want that. I want only main Application. Like if two application are running in my pc then I should get only those application's Name.
View Replies View RelatedI want to use the list element inside my scriptlet. Below is my code which is not working.
<c:forEach var="social" items="${sociallist}">
<%
callToFunction(%>${social}<%);
%>
</c:forEach>
How can i access social var inside scriptlet.