Finding And Printing Median Node In Linked List Using Recursion
Nov 3, 2014
The only problem I have now is getting a method to return the median element of a LinkedList without using loops of any kind or by using a global counter anywhere.
I've pretty easily figured out how to get the index value for the median number (there is some lee way allowed. If the list has an even size, any of the middle values are accepted) but I can't figure out how to print it without loops.
I'm sure I need to make a method that finds an element at the given index value, but I don't know how to do it without loops.
Here's all of my code. Inside is my Assignment3 class I use for testing, StudentList which contains the LinkedList head and other List methods, and StudentNode which is obviously, the Node class. Also I've attached the first test1.txt file as well.
import java.io.FileNotFoundException;
import java.util.*;
public class Assignment3 {
public static void main (String []args){
StudentList<StudentNode> myList = new StudentList<StudentNode>();
[Code] .....
I tried making a method that basically counts up the list recursively then a second method that counts down recursively and is supposed to stop once it hits the middle number, then print that node.
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. **/
I have a custom linkedList(single) class that uses the provided node class. Now I have another class to QuickSort this.(left out for brevity, i just wanna focus on editing the L.head). However, instead of passing the quicksort method the entire linkedList, I want to pass it just the head from the linkedlist.
My problem is accessing this head node and changing it from the quckSort method/class, and I dont want to delete it or simply just change the element value
Main:
public class TestLinkedList { public static <E extends Comparable<E>> void main(String[] args) { MyLinkedList<Integer> L = new MyLinkedList<Integer>(); L.add(3); L.add(1); L.add(2); System.out.println("Initial=" + L); MySort.quickSort(L.head); System.out.println("After ="+L); } }
QuickSort:
public class MySort { public static <E extends Comparable<E>> void quickSort(MyNode<E> list) { list = list.next; }
Node Class:
public class MyNode<E extends Comparable<E>> { E element; MyNode<E> next; public MyNode(E item) { element = item; next = null;
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
Im running into some problems with the Java compiler. This is my code:
public class DoublyLinkedList<T> implements SimpleList<T> { protected Node dummy; protected int n; public DoublyLinkedList(){
dummy = new Node(); dummy.next = dummy; dummy.pre = dummy;
n = 0;
[Code] ....
I want to use a dummy node in my implementation of the Doubly Linked List, so it will be easier to code all the methods I need to write. I keep on getting a problem with line 14 and 15:
dummy.next = dummy;
dummy.pre = dummy;
// cannot find symbol variable next (compiler error)
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');
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;
I'm trying to find the median of a set of numbers inputted into an array and I wanted to know how I would pass the array to the median calculator after I use selection sort to organize the numbers.THIS IS THE CODE THAT ORGANIZES THE ARRAY:
public void selectionSort(double[] myArray) { for (int i = 0; i < myArray.length - 1; i++) { int index = i; for (int j = i + 1; j < myArray.length; j++)
if (myArray[j] < myArray[index])
[code]....
The code that finds the median will only work if the array being used is already organized. How do I pass the new sorted array to the code that finds the median?
I have to alter my Sentence class to find the index of the substring "sip" in Mississippi but I'm really not sure where to begin. This is what I have...
Sentence.java public class Sentence { private boolean outcome; private String sentence; public Sentence(String aSentence) { sentence = aSentence;
[Code] ....
I know that I need to change public boolean find(String t) to public int indexOf(String t) but I'm not sure what to start doing to get the index of "sip".
a simple Java program for finding the median value in a list of values with the following requirements:
- Create an array with an even number of values in it (an odd number of values is little bit trickier, so if you want a challenge, do it for either an even or odd number of values)
- Find the value with an equal number of values greater than the value as there are values less than the value
- Your solution must not require a sorted list of values - Output the median value
This assignment is intended to get you to demonstrate basic knowledge of arrays, and to create methods with both input and output.
The program I'm working on is supposed to read input from a file and using recursion, print the pattern of asterisks for each value until the value is either < 0 or > 25.For example, if the value was 4, the pattern would look like this
* * * * * * * * * * * * * * * *
The values are stored in a file entitled prog3.dat which looks like this
4 3 15 26 0
I've never used recursion before and haven't been able to find anything showing how it would work with this particular type of problem.Here is what I've been able to come up with so far, but I'm having problems still which I will show following the code.
import java.util.Scanner; import java.io.*; public class Program3 { public static void main(String[] args) throws Exception { int num = 0; java.io.File file = new java.io.File("../instr/prog3.dat"); Scanner fin = new Scanner(file);
[code]...
It appears to be reading the file correctly, but is only printing the top half of the pattern. Also, like I said, I'm not very familiar with recursion, so am not sure if this is actually recursion?
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 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.
We have Starting point that is (3,0) and an ending point is (1,3). We can only move up and right to get to the ending point by using recursion. We have to list all possible paths from (3,0) to (1,3)
We have Starting point that is (3,0) and an ending point is (1,3). We can only move up and right to get to the ending point by using recursion. We have to list all possible paths from (3,0) to (1,3)
I was able to get from (3,0) to (1,3) but how to list the other paths. This is my code so far
public class Program7 { public static void main(String[] args){ int size = 5; int x1 = 3; int y1 = 0; int x2 = 1; int y2 = 3; System.out.println(x1+" "+y1); System.out.println(x2+" "+y2);
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 created this code, seems like it should be working properly and the code is right, but the output is not what it should be.The action gets a List<Integer> and should make it reversed.
As example: 1 2 3 4 5 ---> 5 4 3 2 1
The Nodes in the new list (lst2) should be in a reversed position.The code does compile with no errors.I do have Node<T> and List<T> classes
Java Code:
public class NodeReverse { public static void reverse (List<Integer> lst, Node<Integer> node, int counter, List<Integer> lst2, Node<Integer> pos) // Should make lst = lst2 while lst2 is the opposite to lst { node = node.getNext(); counter++; if(node.getNext()!=null) reverse(lst, node, counter, lst2, pos);
I am working on this project that wants me to write a program that inputs 20 numbers, each of which is between 10 and 100, inclusive. As each number is read, display it only if it is not a duplicate of a number already read. The only part I am confused about is how to go about checking for duplicate values that the user may enter. And IF the user does input a duplicate value, it should not be stored again.In addition, the value entered should be printed out after it is entered along side the value that have been previously entered by the user such as:
23 23 45 23 45 67 23 45 67 12 and so on.
I am still fairly new at java programming.
import java.util.*; public class NumberArray { public static void main(String[] args) { // declare an array with 5 elements
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.
