How To Traverse And Search For Element In Linked List
Nov 11, 2014
I have to make a method called search that goes through the linked list and checks to see if whatever String the user entered matches a String in the linked list. With this code, every time I enter an existing String it outputs "There is no element that contains that information". How come?
public class LinkedListExample {
List InfoList = new LinkedList();
public void doLinkedListExample()
{ // add original data to linked list
InfoList.add("Computer"); // string (original 3 elements)
InfoList.add("Programs");
InfoList.add("in Java");
I have to make a program that allows the user to make a linked list of Strings (names) and then choose who to eliminate.
For example: Five people in a linked list of Strings: I would like the program to ask the user to choose a number between 1 and 5. If the user chooses number 2, Mary is the second person in the linked list so she gets eliminated.
The problem is that I'm not sure how to traverse through the linked list because they are of type String value, and I am looking for the name using the corresponding integer I mentioned above. I think I have to use Nodes? Not very sure where to start right now.Here is my code:
This is my first time using linked lists and for homework I have to make a program that allows the user to make a linked list of Strings (names) and then choose who to eliminate. For example,
Five people in a linked list of Strings: Joe, Mary, Sue, Tom, Hannah.
I would like the program to ask the user to choose a number between 1 and 5. If the user chooses number 2, Mary is the second person in the linked list so she gets eliminated.
The problem is that I'm not sure how to traverse through the linked list because they are of type String value, and I am looking for the name using the corresponding integer I mentioned above.
Here is my code:
package llchallenge; import java.util.LinkedList; import java.util.List; import java.util.ListIterator; import java.util.Scanner; public class LLChallenge { List JosephusList = new LinkedList(); // order of names
AddItemToFront(Item p) : This method will create a new Node with the Item object as its data value and then add the newly created node to the front of the linked list.
DisplayItems(): This method will traverse the linked list from first node to last node and print data value ( i.e., id, name, type and price of the Item object) of each node.
RemoveItemAtPosition(int n): This method will remove the node at position n in the linked list. Assume that the first node of the linked list has a position number of 1 and the second node has a position number of 2 and so on.
This is my Code
AddItemToFront public void AddItemtoFront(Item p) { Node newNode = new Node(p); newNode.setLink(head); head = newNode;
[Code] ....
I don't know what am I suppose to do inside the remove method
I just trying to find the most efficient way to do this. I read in a csv file into a linked list and then I split the linked list into sections based on category for each element. Of course I used an array to split each element of the list. However I can do the sequential search by either ID and Name by using hashmap and making the key = name + ID and then doing key.contains(charSequence);. However I feel like this is inefficient and I would like to use the linked list instead of a hashmap which could be done by splitting the user input and used for method overloading by passing an int in one and a string in another. I feel like this approach is a little more redundant and maybe their is a better approach for searching for id and name. Below is an example of the elements in a linked list.
note: their are more elements than this.
element 1
name: George address: 4410 something dr. phone number: 978-888-6666 id: 43
element 2
name: Karla address: 339 something dr. phone number: 334-338-6556 id: 23
I am very new to coding and I am struggling with one of my intro to Java Projects. This project involves creating a GUI that has a list of trees and their possible heights, giving each tree a range for their possible minimum and maximum heights.
I am having trouble creating this method for the TreeDatabase (TreeDB class):
public String queryByPossibleHeight(int key) Instructions for this method are as follows: this method creates and returns a single string that contains the trees that can be found such that the value key is in the range for possible height. Traverse the entire ArrayList of Trees and for each one of the trees contained in the ArrayList invoke the method inRange() from the class Tree. Pass to the method inRange() the parameter key. If inRange() returns true, invoke the method toString() from the class Tree. Append the value returned by invoking the method toString() to the String result, adding a “” at the end. Once the entire ArrayList has been traversed, return the String result.
My 3 classes so far (I haven't gotten to the actual GUI yet):
public class Range { private int low; private int high; private int value; public Range(int plow,int phigh){ low = plow; high = phigh;
[Code]...
As you can see in the last TreeDB class, in the public String queryByPossibleHeight(int key) method I have something wrote in, but I was just testing random things.
Suppose 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 ?
I have to create a program that asks a user to enter an amount for rows and an amount for columns. After they input both amounts, they must fill in the matrix with values (values of double data type). After they enter the values, the program is suppose to search the matrix for the element with the highest value. Once it is found, the user will be prompted with the location of the highest value within the array. I got it to work as to where the user inputs the values and he/she will receive a location of an element. However what they receive is incorrect.
For example
"Enter number of rows: 3 Enter number of columns: 4 Enter values: 23.5 6 13 2 1 5 6 3 7 5 9 2"
Once they enter the last value, they will be prompted with
"The highest element is located in 34".
As you can tell, the highest element is located in 01. I think when the user is prompted with the values that they enter for the rows and columns. How can I modify my code as to where it shows the actual location of the highest value?
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.
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'm trying to use LinkedBinarySearchTree but a lot of the variables are protected in BinaryTreeNode. I am creating a BinaryTreeNode object but it still isn't allowing me to use them. The variables I am trying to use are element, left, and right.
import ch11.exceptions.*; import ch10.LinkedBinaryTree; import ch10.BinaryTreeNode; /** * LinkedBinarySearchTree implements the BinarySearchTreeADT interface with links.
*/ public class LinkedBinarySearchTree<T> extends LinkedBinaryTree<T> implements BinarySearchTreeADT<T>
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) {
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;
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;
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.
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
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.
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.
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..
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.
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) {
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');
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); } }
I am trying to advance to the next node in my linkedList. Below is what i have so far.
/** * Move forward, so that the current element is now the next element in this sequence. * @param - none * @precondition: * isCurrent() returns true. * @postcondition: * If the current element was already the end element of this sequence (with nothing after it), then there is no longer any current element. * Otherwise, the new element is the element immediately after the original current element. * @exception IllegalStateException * Indicates that there is no current element, so advance may not be called. **/
