Singly-linked List Program Challenges
Oct 22, 2014
read a text file that has some polynomials in a specific format and perform an arithmetic expression. This needs to be done using a singly-linked list to store the coefficients of the polynomials. There needs to be two methods, one that adds the two polynomials and one to multiply them. So for example suppose i had the following set of polynomials in the text file:
2+x2-3x3 and 1-x-2x2+3x3
these are represented by 2, 0, 1, -3 and 1, -1, -2, 3 respectively. The of the two polynomials is: 3-x-x2 which is represented as: 3, -1, -1
The product of the two polynomials is: 2-2x-3x2+2x3+x4+9x5-9x6
My code is just echoing the data in the text file and not actually doing any arithmetic.
import java.io.*;
import java.util.Scanner;
class Node {
public int digi1;
public int digi2;
public Node nxt;
[code]....
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Oct 30, 2014
I searched a lot but can't seem to understand the sorting of a SLLNode... I noticed a method called Bubble Sort, I understand how it works, but can't think of a way to implement it to my code..
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Apr 17, 2015
I am trying to implement a singly linked list. My singly linked list, where I implemented a class named linkedlist, that I defined (this implementation of linkedlist is not the java class linkedlist, it is my own version of linkedlist):
Java Code:
public class SinglyLinkedList<E> implements LinkedList<E> {
public class Node<E> {
public Node<E> next;
public E element;
public Node(E element) {
this.element = element;
}
public Node (E element, Node<E> next) {
[code]...
But when I go to my main method to add into my SinglyLinkedList, it doesn't add anything.
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Apr 26, 2015
Implementing the add(int i, E o) method for a SinglyLinked List.
public void add(int i, E o)
// pre: 0<=i<= size()
// post: adds ith entry of list to o
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Sep 30, 2014
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.
package project;
public class GameEntry implements Comparable<GameEntry> {
private String name;
private int score;
public GameEntry(String n, int s) {
name = n;
score = s;
[code]...
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Jul 16, 2014
I'm still working with the singlylinkedlist data structure and trying to return a string of individual characters stored in each node. ( head--('J')---('A')---('V')---('A')---tail ) Hopefully this beautifully executed depiction to the left will clarify.
This is what I came up with after designing the algorithm w/ pen and paper. I know that I'm not accounting for the OutOfBound errors, an empty list, or an index < 0.... I will get to that.
Right now, I'm not sure why my assignment to the character array, ' chars[i] = cursor.getLink(getElement()); ' , is not working. The two methods getLink and getElement, type Node and T, respectively, exist in my Node class which is a private nested class in MySLList. Why would I be getting the following error: "The method getElement() is undefined for the type StringX" ? Is this a good design and implementation of the substring method?
public String substring(int index) {
char[] chars = new char[(getSize() - index)]; //getSize() defines the size of list in MySLList
Node cursor = null;
//Set the cursor to the node = index
if(cursor == head) {
[Code] ....
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Oct 27, 2014
So I'm trying to build a queue, first in first out, (so add to the head remove from the end) using a linked list for use in another program, I'm having a problem dequeueing where the program seems to run indefinitely without giving an answer, so my suspicion is its caught in a while loop but how and why I can't figure out.
public class CircularQueuelist {
private Node head = null;
private int size = 0;
private class Node
{
int data;
Node next;
[Code] ....
My logic seems sound, I basically look for when the second node over from the current one I'm on is a reference to the head, and then skip the one in front of it using setting currents. next link to current.next = head, severing the link to the last node.
This is what my driver looks like, I enqueue items 1-10 and then use the iterator to make sure it worked out fine and check size, its when I dequeue that I run into a problem, the program runs indefinitely.
public class Queuetest {
public static void main(String[]args)
{
CircularQueuelist test = new CircularQueuelist();
for (int count = 0; count < 10; count ++)
[Code] ....
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May 6, 2015
I am trying to implement product method below which returns the set representing the Cartesian product of the current set and a given set (the Cartesian product contains all ordered pairs (a, b) where a belongs to the current set, and b belongs to the given set). The product should be a ListSet <Tuple<E>> object where each ordered pair is a Tuple element. (I have a Tuple class which implements an ordered tuple)
What am I trying to do in the product method : Make 2 for loop and inside the for loop make an array of <E> then set the 2 elements of the tuple then again set tuple and add it to arrayList. how to set 2 elements of the tuple and set tuple ??
public class ListSet<E> implements Iterable<E>{
SinglyLinkedList<E> sl;
public ListSet(){
sl = new SinglyLinkedList<E>();
[code]....
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Jul 27, 2014
I'm trying to build a program that contains the ability to:
(1) insert new node at head,
(2) print out contents of the list in order,
(3) remove first node from head,
(4) remove last node from tail,
(5) find a target value,
(6) give total number of occurrences of a target value, and
(7) give total number of items in list.
The areas I'm struggling with implementing are: (
- remove from tail - I know how to find the final node but I can't quite figure out how to set it to null since its initial type is an integer.
- find a target value - how to make the parameters quite workout so the user can simply input an integer value.
- The solution is probably really simple but I can't figure out how to print out the results of these methods when I call them.
public class Node
{
private int data;
private Node link;
// Node Constructor 1
public Node()
{
data = 0;
link = null;
[code]....
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Nov 18, 2014
I want to create java program in which i want to inherit stack and queue from a linked list class and also make infix to postfix inherit from stack and periority queue from queue class.Ho can i make this program.
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May 12, 2015
Write a java program to store employee information in a linked list, the program should implement the following functions:
The program should display the list of functions, and ask the user to enter the number of function that he/she wants to do, then perform the function as it is required in the previous table.
import java.util.*;
public class Employee {
Scanner in = new Scanner(System.in);
String Name;
String Address;
String Department;
int ID;
int Salary;
[code]....
this is my out put
Please choose a number:
1-Add a new employee
2-Update employee's info
3-Remove employee's info
4-Exit
1
Enter name:
Enter address:
2
Enter department:
3
Enter ID:
4
Enter salary:
now:
1- why are not my adding coming out in the output only the Enter name & Enter address ??
2- how can I add names and ID's and information to test that program
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Feb 14, 2014
I 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.
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Oct 5, 2013
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?
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Oct 6, 2014
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]....
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Mar 21, 2014
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;
[code].....
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Jan 30, 2014
I'm trying to implement an Office class that contains an inner class: WorkerNode. The WorkerNode class has a name attribute (String) and WorkerNode attributes for boss, peer and subordinate. The attributes of Office are manager and current which are WorkerNode references. The manager refers to the entry point of the structure and current is the current node in the structure. For simplicity, i'm going to try to limit it to 3 levels and assume that the names are unique. I've put together a Office class that containing main and provided the code I've worked on so far.
public class Office {
public static void main(String[] args) {
String name=Input.getString("input the manager's name: ");
Office office=new Office(name);
int option;
[code]....
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Apr 20, 2014
I have made a node class and im trying to implement a sorting method. I must use a selection sort but with specific instructions: "Your method should not need to use the new operator since it is just moving nodes from one list to another( not creating new nodes)
this is my current implementation ..but i am instantiating new object..
public class NodeInt
{
private int data;
private NodeInt next = null;
public NodeInt(){}
//precondition:
//postcondition:
public NodeInt(int data, NodeInt next)
{
this.data = data;
this.next = next;
[code]....
edit: this is the part that worked but i had it commented out so i have the previous and current declared above but didnt copy.
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Apr 30, 2014
Ok here I have a code that generates 1 million random values then converts them to a string then hashcode. I then insert into a linked list and then I want to run through each hash and find it in the linked list timing each run then averaging out the time at the end.
It works great for smaller amounts of numbers it is searching for (fine under 50 thousand searches for the for loop starting at line 24 LinkedListTest.java) but when I try to do the full million searches it gives me "a Exception in thread "main" java.lang.StackOverflowError" at line 158 in List.java. Maybe im getting tired but I cannot figure out why.
// class to represent one node in a list
class ListNode< T >
{
// package access members; List can access these directly
T data; // data for this node
ListNode< T > nextNode; // reference to the next node in the list
[code]....
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May 1, 2014
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.
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Apr 10, 2014
I am writing a Twitter app, and I am encountering an error whenever I attempt to find the user's name from a screen name. I get the following error:
04-10 21:43:57.402: W/System.err(9326): No authentication challenges found
Which means that somehow, I'm not logged in. However, I am able to post, get the timeline statuses and even get the User of each status. I simply cannot do this:
public String getUserFromScreenName(String screenName) throws TwitterException {
m_twitter.verifyCredentials();
return m_twitter.showUser(screenName).getName();
}
The m_twitter.verifyCredentials() PASSES, which means I am authenticated, and the following line somehow I am not.
My m_twitter is defined here:
public void authenticate(String token, String secret) {
m_accessToken = token;
m_accessSecret = secret;
ConfigurationBuilder cb = new ConfigurationBuilder();
cb.setOAuthConsumerKey(m_consumerKey)
[Code] .....
And as I said before, I can read/post/retweet and all that stuff both before AND after this call, but this one simply will not work.
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Jan 31, 2015
if 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.
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Dec 30, 2014
Is there a particular implementation of a linked list you are referring to in your question?
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Dec 11, 2014
I'm having some trouble with figuring out how to move along a doubly linked list for an assignment. The program is supposed to be a simple board game simulation. Here is what I have so far:
Space.java:
public class Space
{
private String name;
public Space next;
public Space previous;
public Space(String name)
{
this.name = name;
[Code]...
I seem to have been able to get all the other methods working properly, but I am pretty stuck on how to do the movePlayer. Specifically because it is passing an integer, but my objects are of type Space and Boardgame.
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Oct 17, 2014
i tried everything but its giving me errors. i tried the for loop but its giving me something else.
this is what i have to do Write a recursive method that prints out the data elements of a linked list in reverse order.
Your method should take in as a parameter the head reference to a linked list. Then, write a recursive method that returns a count of the number of elements greater than a given threshold. You may assume that the data elements in the linked lists are ints. The parameters of your method are a reference to the linked list and a int value representing the threshold.
public class recursion3
{
public static void main(String [] args) {
char a [] = {'A', 'B','C','D','E'};
System.out.println(a);
}
public static String reverseString(String s) {
if (s.length() <= 1) {
[code]....
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Feb 17, 2015
I'm trying to print the contents of my linked list. I'm using nodes and within those nodes it hold String data. So i want to print out the data within the nodes. Whenever i do
System.out.println(node1.data),
it prints perfectly. But i'm trying to use a method where it would loop through the list and print out the data for every node in it. when i run my print method i get results such as
Node@15db9742
Node@6d06d69c
Node@7852e922.
Here is my print method i created
Java Code:
public void print(){
Node<E> current = head;
while (current.next != null){
System.out.println(current.data);
current = current.next;
}
} mh_sh_highlight_all('java');
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Apr 12, 2014
I am creating a recursive method to reverse a linked list in java. It works the first time when I call it, but I want it to work where I call it a second time and it reverses it to the original state. How can I get that to work with this implementation?
public void reverseList() {
System.out.printf("%-16s%-3s%n", "Name", "Score");
System.out.println("--------------- -----");
reverseList(first);
} public void reverseList(Node aNode) {
if (aNode != null) {
reverseList(aNode.next);
System.out.printf("%-15s%6s%n" , aNode.name , aNode.score);
}
}
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