Creating A Linked List. C#

Creating A Linked List. C# - c#

I've tried creating linked list/node classes and I'm not sure where to go next. My attempts haven't went well because after creating the classes I'm just not sure what the next step is.
I'm trying to create a program that has a dinosaur node which saves information about the dinosaur such as id, species etc and I want to allow the user to create and remove dinosaurs from the list. So I need to allow the user to input data, I assume there's a way to make dino id get set automatically but I'm not to sure.
I've included the LinkedList.cs and the Node.cs so you can see where I'm going but I have no idea what to do within my program class to utilise the linked list and achieve what I'm trying to do.
Added Program.cs class incase that helps identify/show where I am within the program/what I need to do.
Linked List Class:
using System;
using System.Collections.Generic;
using System.Runtime.ExceptionServices;
using System.Text;
namespace JurrasicFinal
{
public class LinkedList
{
private Node head;
private int count;
public LinkedList()
{
this.head = null;
this.count = 0;
}
public bool Empty
{
get { return this.count == 0; }
}
public int Count
{
get { return this.count; }
}
public object this[int index]
{
get { return this.Get(index); }
}
public object Add(int index, object o)
{
if (index < 0)
throw new ArgumentOutOfRangeException("Index: " + index);
if (index > count)
index = count;
Node current = this.head;
if (this.Empty || index == 0)
{
this.head = new Node(o, this.head);
}
else
{
for (int i = 0; i < index - 1; i++)
{
current = current.Next;
current.Next = new Node(o, current.Next);
}
}
count++;
return o;
}
public object Add(object o)
{
return this.Add(count, o);
}
public object Remove(int index)
{
if (index < 0)
throw new ArgumentOutOfRangeException("Index: " + index);
if (this.Empty)
return null;
if (index >= this.count)
index = count - 1;
Node current = this.head;
object result = null;
if (index == 0)
{
result = current.Data;
this.head = current.Next;
}
else
{
for (int i = 0; index < index - 1; i++) ;
current = current.Next;
result = current.Next.Data;
current.Next = current.Next.Next;
}
count--;
return result;
}
public void Clear()
{
this.head = null;
this.count = 0;
}
public int IndexOf(object o)
{
Node current = this.head;
for (int i = 0; i < this.count; i++)
{
if (current.Data.Equals(o))
return i;
current = current.Next;
}
return -1;
}
public bool Contains(object o)
{
return this.IndexOf(o) >= 0;
}
public object Get(int index)
{
if (index < 0)
throw new ArgumentOutOfRangeException("Index: " + index);
if (this.Empty)
return null;
if (index >= this.count)
index = this.count - 1;
Node current = this.head;
for (int i = 0; i < index; i++)
current = current.Next;
return current.Data;
}
}
}
Node Class:
using System;
using System.Collections.Generic;
using System.Text;
namespace JurrasicFinal
{
public class Node
{
private object data;
private Node next;
private string DinoSpecies;
private string DinoName;
public Node(object data, Node next)
{
this.data = data;
this.next = next;
}
public object Data
{
get { return this.data; }
set { this.data = value; }
}
public Node Next
{
get { return this.next; }
set { this.next = value; }
}
}
}
Program Class:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq.Expressions;
namespace JurrasicFinal
{
class Program
{
class Dinosaur
{
public string Name;
public string Classification;
public char Sex;
}
static void Main(string[] args)
{
LinkedList<Dinosaur> DinoList = new LinkedList<Dinosaur>();
Dinosaur Dino1 = new Dinosaur();
Dino1.Name = "Tyrannosaurus Rex";
Dino1.Classification = "Carnivorous";
Dino1.Sex = 'M';
Dinosaur Dino2 = new Dinosaur();
Dino2.Name = "Velociraptor";
Dino2.Classification = "Carnivorous";
Dino2.Sex = 'F';
Dinosaur Dino3 = new Dinosaur();
Dino3.Name = "Procompsognathus";
Dino3.Classification = "Carnivorous";
Dino3.Sex = 'M';
void printList()
{
Console.WriteLine("Current Queue: ");
Console.WriteLine("\n");
foreach (Dinosaur d in DinoList)
{
Console.WriteLine("Name: " + d.Name);
Console.WriteLine("Classification: " + d.Classification);
Console.WriteLine("Sex " + d.Sex);
Console.WriteLine("\n");
}
Console.WriteLine(Dino1.Name + Dino1.Sex);
}
DinoList.AddLast(Dino1);
DinoList.AddLast(Dino2);
DinoList.AddLast(Dino3);
printList();
Console.WriteLine(DinoList.Count);
FileStream fileStream = File.OpenWrite("E:/Work/Dinosaur.txt");
BinaryWriter writer = new BinaryWriter(fileStream);
foreach (Dinosaur d in DinoList)
{
writer.Write(d.Name);
writer.Write(d.Classification);
writer.Write(d.Sex);
}
writer.Close();
Console.WriteLine("Reading Back From File");
FileStream file = File.OpenRead("E:/Work/Dinosaur.txt");
BinaryReader reader = new BinaryReader(file);
for (int i = 1; i < 3; i++)
{
Dinosaur d = new Dinosaur();
d.Name = reader.ReadString();
d.Classification = reader.ReadString();
d.Sex = reader.ReadChar();
DinoList.AddLast(d);
}
reader.Close();
Console.ReadKey();
}
}
}

I think you might be looking for something like this, which hangs on user input and tries to do simple validation. I made it a bit overly complex to demonstrate some options.
class Sample
{
private static int index = 0;
static void Main(string[] args)
{
LinkedList<Dinosaur> DinoList = new LinkedList<Dinosaur>();
while (true)
{
var dino = new Dinosaur();
dino.Name = GetInput("Enter dino name (q to quit): ");
if (dino.Name == "q" || dino.Name == "Q")
{
break;
}
dino.Classification = GetInput("Enter dino classification: ");
char[] sexes = new char[] {'F', 'f', 'M', 'm'};
while (true)
{
Console.WriteLine("Enter dino sex (M/F): ");
dino.Sex = (char) Console.Read();
if (sexes.Contains(dino.Sex))
{
break;
}
}
int inputIndex = default;
while (true)
{
var indexString = GetInput($"Enter 0-index list position (max {DinoList.Count})");
inputIndex = Convert.ToInt32(indexString);
if (inputIndex <= DinoList.Count)
{
break;
}
}
DinoList.Add(inputIndex, dino);
index++;
Console.WriteLine("Dinosaurs:");
Console.WriteLine(new string('-', 30));
for (var i = 0; i < DinoList.Count; i++)
{
var dinosaur = (Dinosaur) DinoList.Get(i);
Console.WriteLine("Name: " + dinosaur.Name);
Console.WriteLine("Classification: " + dinosaur.Classification);
Console.WriteLine("Sex: " + dinosaur.Sex);
}
}
}
private static string GetInput(string prompt)
{
Console.WriteLine(prompt);
var input = Console.ReadLine();
while (string.IsNullOrWhiteSpace(input))
{
input = Console.ReadLine();
}
return input;
}
}
Note that you have to make your LinkedList and Node into LinkedList<T> and Node<T> but they converted directly, so it's just a bit of typing.
Hope it helps!
Edit: Add classes provided in question, modified to be generic.
public class Node<T>
{
private object data;
private Node<T> next;
private string DinoSpecies;
private string DinoName;
public Node(object data, Node<T> next)
{
this.data = data;
this.next = next;
}
public object Data
{
get { return this.data; }
set { this.data = value; }
}
public Node<T> Next
{
get { return this.next; }
set { this.next = value; }
}
}
public class LinkedList<T>
{
private Node<T> head;
private int count;
public LinkedList()
{
this.head = null;
this.count = 0;
}
public bool Empty
{
get { return this.count == 0; }
}
public int Count
{
get { return this.count; }
}
public object this[int index]
{
get { return this.Get(index); }
}
public object Add(int index, object o)
{
if (index < 0)
throw new ArgumentOutOfRangeException("Index: " + index);
if (index > count)
index = count;
Node<T> current = this.head;
if (this.Empty || index == 0)
{
this.head = new Node<T>(o, this.head);
}
else
{
for (int i = 0; i < index - 1; i++)
{
current = current.Next;
current.Next = new Node<T>(o, current.Next);
}
}
count++;
return o;
}
public object Add(object o)
{
return this.Add(count, o);
}
public object Remove(int index)
{
if (index < 0)
throw new ArgumentOutOfRangeException("Index: " + index);
if (this.Empty)
return null;
if (index >= this.count)
index = count - 1;
Node<T> current = this.head;
object result = null;
if (index == 0)
{
result = current.Data;
this.head = current.Next;
}
else
{
for (int i = 0; index < index - 1; i++) ;
current = current.Next;
result = current.Next.Data;
current.Next = current.Next.Next;
}
count--;
return result;
}
public void Clear()
{
this.head = null;
this.count = 0;
}
public int IndexOf(object o)
{
Node<T> current = this.head;
for (int i = 0; i < this.count; i++)
{
if (current.Data.Equals(o))
return i;
current = current.Next;
}
return -1;
}
public bool Contains(object o)
{
return this.IndexOf(o) >= 0;
}
public object Get(int index)
{
if (index < 0)
throw new ArgumentOutOfRangeException("Index: " + index);
if (this.Empty)
return null;
if (index >= this.count)
index = this.count - 1;
Node<T> current = this.head;
for (int i = 0; i < index; i++)
current = current.Next;
return current.Data;
}
}

Related

Add another item in array without built-in functions

The following script is working fine. But need to add one more item in array without built-in function. Is it possible to do without Resize() ?
string[] data = {"item-1", "item-2"};
Array.Resize(ref data, 3);
data[2] = "item-3";
foreach(string i in data) {
Console.WriteLine(i);
}

No. Arrays are fixed size, so the only way to add more stuff to them is to resize them.
If you have a scenario where you need to add a dynamic number of elements, use List<T> instead.

Assuming you're trying to increase the size of an array without any built-in libraries or data structures, you just need to create a new larger array, copy the old elements, then add your new element.
string[] data = {"item-1", "item-2"};
string[] newData = new string[data.Length + 1];
int i;
for (i = 0; i < data.Length; i++) {
newData[i] = data[i];
}
newData[i] = "item-3";
Console.WriteLine(newData[2]);

The short answer is no. But if you want you can always implement a logic that does the resizing. You could do something like this implementation of a List:
public class List<T> : IAbstractList<T>
{
private const int DEFAULT_CAPACITY = 4;
private T[] _items;
public List()
: this(DEFAULT_CAPACITY) {
}
public List(int capacity)
{
if (capacity < 0)
{
throw new ArgumentOutOfRangeException(nameof(capacity));
}
this._items = new T[capacity];
}
public T this[int index]
{
get
{
this.ValidateIndex(index);
return this._items[index];
}
set
{
this.ValidateIndex(index);
this._items[index] = value;
}
}
public int Count { get; private set; }
public void Add(T item)
{
this.GrowIfNecessary();
this._items[this.Count++] = item;
}
public bool Contains(T item)
{
for (int i = 0; i < this.Count; i++)
{
if (this._items[i].Equals(item))
{
return true;
}
}
return false;
}
public int IndexOf(T item)
{
for (int i = 0; i < this.Count; i++)
{
if (this._items[i].Equals(item))
{
return i;
}
}
return -1;
}
public void Insert(int index, T item)
{
this.ValidateIndex(index);
this.GrowIfNecessary();
for (int i = this.Count - 1; i > index; i--)
{
this._items[i] = this._items[i - 1];
}
this._items[index] = item;
this.Count++;
}
public bool Remove(T item)
{
var index = this.IndexOf(item);
if (index == - 1)
{
return false;
}
this.RemoveAt(index);
return true;
}
public void RemoveAt(int index)
{
this.ValidateIndex(index);
for(int i = index; i < this.Count - 1; i++)
{
this._items[i] = this._items[i + 1];
}
this._items[this.Count - 1] = default;
this.Count--;
}
public IEnumerator<T> GetEnumerator()
{
for (int i = 0; i < this.Count; i++)
{
yield return this._items[i];
}
}
IEnumerator IEnumerable.GetEnumerator()
=> this.GetEnumerator();
private void ValidateIndex(int index)
{
if (index < 0 || index >= this.Count)
{
throw new IndexOutOfRangeException(nameof(index));
}
}
private void GrowIfNecessary()
{
if (this.Count == this._items.Length)
{
var array = new T[this.Count * 2];
Array.Copy(this._items, array, this._items.Length);
this._items = array;
}
}
}
The above sample code can give you ideas about implementing other methods that need array resizing as well.

C# Binary Tree, Max and Min Value

I wrote some code and have some problems, but the most important question is: why is the array not working with AddNode? I know I am close to solving this problem, but I hope for a little hint.
Next question: the code for Min and Max value is good. How can I move it to Class Node?
And the last question: how to make Class Depth for tree?
class Node
{
public Node LeftNode { get; set; }
public Node MiddleNode { get; set; }
public Node RightNode { get; set; }
public int Value { get; set; }
public void AddNode(int value)
{
if (value < this.Value)
{
if (LeftNode != null)
{
LeftNode.AddNode(value);
return;
}
LeftNode = new Node(value);
return;
}
if (value > Value)
{
if (RightNode != null)
{
RightNode.AddNode(value);
return;
}
RightNode = new Node(value);
return;
}
if (MiddleNode != null)
{
MiddleNode.AddNode(value);
return;
}
MiddleNode = new Node(value);
}
public Node(int value)
{
this.Value = value;
}
public override string ToString()
{
return $"Value: {Value}";
}
public string SortedString(Array arr)
{
Array.Sort(arr);
foreach (int val in arr)
{
Console.WriteLine(val);
}
return "";
}
public int ValueCount(int value)
{
if (value < Value)
{
if (LeftNode == null)
{
return -1;
}
return LeftNode.ValueCount(value);
}
if (value > Value)
{
if (RightNode == null)
{
return -1;
}
return RightNode.ValueCount(value);
}
if (MiddleNode != null)
{
return 1 + MiddleNode.ValueCount(value);
}
return 1;
}
internal int Next(int min, int max)
{
Random rnd = new Random();
return rnd.Next(min, max);
}
}
class Program
{
static void Main(string[] args)
{
var arr = new int[1000];
var rnd = new Node(1);
for (int i = 0; i < arr.Length; i++)
{
rnd.AddNode(arr[i]);
//Console.WriteLine(arr[i]);
}
for(int i = 0; i < arr.Length; i++)
{
arr[i] = rnd.Next(1, 100);
Console.WriteLine(arr[i]);
}
min = arr[0];
max = arr[0];
for (int i = 1; i < arr.Length; i++)
{
if (min > arr[i])
min = arr[i];
if (max < arr[i])
max = arr[i];
}
Console.WriteLine("największa liczba" + " " + max);
Console.WriteLine("najmniejsza liczba" + " " + min);
Array.Sort(arr);
foreach (int value in arr)
{
Console.WriteLine(value);
}
Console.WriteLine(rnd.ValueCount(6));
Console.WriteLine(rnd.ToString());
}
}

To be honest - your code is a bit confusing.
first of all - why do you have a pointer (ref) to a middle node ? A binary tree defines each node to have at most 2 children (left \ right).
If you wish to handle duplicate values you can either choose a strategy that defines one of the children to also includes equals, or better use ref count (e.g.: each node has both a value and a counter for this value).
re Min \ Max - if your tree is a BST (which it seems to be the case), you can easily implement this through simple tree traversing either to the left (for Min value) or to the right (for max value).

Checking if singly-linked list is palindrome or not

This is my code.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace LinkedList
{
public class Node
{
public int data;
public Node next;
public Node(int data)
{
this.data = data;
next = null;
}
}
public class MyList
{
public Node head;
public MyList()
{
head = null;
}
public void addNode(int data)
{
if(head == null)
{
head = new Node(data);
}
else
{
Node temp = new Node(data);
Node current = head;
while(current.next != null)
{
current = current.next;
}
current.next = temp;
}
}
public void print()
{
if(head == null)
{
Console.WriteLine("List is already empty!");
}
else
{
Node current = head;
while (current != null)
{
Console.Write("|" + current.data + "|-> ");
current = current.next;
}
Console.WriteLine();
}
}
public void addToStart(int data)
{
if(head == null)
{
head = new Node(data);
}
else
{
Node temp = new Node(data);
temp.next = head;
head = temp;
}
}
public void addSorted(int data)
{
if(head == null)
{
head = new Node(data);
}
else if(data < head.data)
{
addToStart(data);
}
else
{
Node current = head.next;
Node previous = head;
Node temp = new Node(data);
while(current != null)
{
if(data < current.data)
{
previous.next = temp;
temp.next = current;
break;
}
previous = current;
current = current.next;
}
}
}
public void removeLast()
{
if(head == null)
{
Console.WriteLine("List is already empty!");
}
else if(head.next == null)
{
head = null;
}
else
{
Node current = head.next;
Node previous = head;
while(current.next != null)
{
previous = current;
current = current.next;
}
previous.next = null;
}
}
public bool isPalindrome()
{
List<int> arr1 = new List<int>();
int i = 0;
Node current = head;
while (current != null)
{
arr1.Add(current.data);
current = current.next;
i++;
}
int[] arr3 = arr1.ToArray();
int count = i;
int[] arr2 = new int[count];
int j = 0;
for (int x = i - 1; x >= 0; x--)
{
arr2[j] = arr3[x];
}
for (int k = 0; k < count; k++)
{
if (arr3[k] != arr2[k])
{
return false;
}
}
return true;
}
}
class Program
{
static void Main(string[] args)
{
MyList a = new MyList();
a.addNode(1);
a.addNode(2);
a.addNode(5);
a.addNode(2);
a.addNode(1);
a.print();
if(a.isPalindrome())
{
Console.WriteLine("Linked List is Palindrome!");
}
else
{
Console.WriteLine("Linked List is Not Palindrome!");
}
}
}
}
My code returns false for the palindrome function every time except when I enter only one value in the linked list.
Also let me know if my method of List<int> is okay or not because I needed it for the palindrome check.

Thankyou for your comments, This is how i solved it.
public bool isPalindrome()
{
int i = 0;
Node current = head;
Node temp = head;
while (temp != null)
{
temp = temp.next;
i++;
}
int[] arr1 = new int[i];
int count = i;
for (int j = 0; j < count; j++)
{
arr1[j] = current.data;
current = current.next;
}
int[] arr2 = new int[count];
int z = 0;
for (int x = i - 1; x >= 0; x--)
{
arr2[z] = arr1[x];
z++;
}
for (int x = 0; x < count; x++)
{
if (arr1[x] != arr2[x])
{
return false;
}
}
return true;
}

C# Display a Binary Search Tree in Console

I have simple binary search tree
public class BNode
{
public int item;
public BNode right;
public BNode left;
public BNode(int item)
{
this.item = item;
}
}
public class BTree
{
private BNode _root;
private int _count;
private IComparer<int> _comparer = Comparer<int>.Default;
public BTree()
{
_root = null;
_count = 0;
}
public bool Add(int Item)
{
if (_root == null)
{
_root = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(_root, Item);
}
}
private bool Add_Sub(BNode Node, int Item)
{
if (_comparer.Compare(Node.item, Item) < 0)
{
if (Node.right == null)
{
Node.right = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(Node.right, Item);
}
}
else if (_comparer.Compare(Node.item, Item) > 0)
{
if (Node.left == null)
{
Node.left = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(Node.left, Item);
}
}
else
{
return false;
}
}
public void Print()
{
Print(_root, 4);
}
public void Print(BNode p, int padding)
{
if (p != null)
{
if (p.right != null)
{
Print(p.right, padding + 4);
}
if (padding > 0)
{
Console.Write(" ".PadLeft(padding));
}
if (p.right != null)
{
Console.Write("/\n");
Console.Write(" ".PadLeft(padding));
}
Console.Write(p.item.ToString() + "\n ");
if (p.left != null)
{
Console.Write(" ".PadLeft(padding) + "\\\n");
Print(p.left, padding + 4);
}
}
}
}
where I can insert values like
BTree btr = new BTree();
btr.Add(6);
btr.Add(2);
btr.Add(3);
btr.Add(11);
btr.Add(30);
btr.Add(9);
btr.Add(13);
btr.Add(18);
I want to display my tree within my console application. I have a btr.Print(); which displays my tree from left to right (6 is the root) - but I'm not happy with it.
Question: Is there a better way to display this tree within a console application? Even a improvement of this Print() would help me.

I've ended up with the following method that allows you to print arbitrary subtree:
public static class BTreePrinter
{
class NodeInfo
{
public BNode Node;
public string Text;
public int StartPos;
public int Size { get { return Text.Length; } }
public int EndPos { get { return StartPos + Size; } set { StartPos = value - Size; } }
public NodeInfo Parent, Left, Right;
}
public static void Print(this BNode root, string textFormat = "0", int spacing = 1, int topMargin = 2, int leftMargin = 2)
{
if (root == null) return;
int rootTop = Console.CursorTop + topMargin;
var last = new List<NodeInfo>();
var next = root;
for (int level = 0; next != null; level++)
{
var item = new NodeInfo { Node = next, Text = next.item.ToString(textFormat) };
if (level < last.Count)
{
item.StartPos = last[level].EndPos + spacing;
last[level] = item;
}
else
{
item.StartPos = leftMargin;
last.Add(item);
}
if (level > 0)
{
item.Parent = last[level - 1];
if (next == item.Parent.Node.left)
{
item.Parent.Left = item;
item.EndPos = Math.Max(item.EndPos, item.Parent.StartPos - 1);
}
else
{
item.Parent.Right = item;
item.StartPos = Math.Max(item.StartPos, item.Parent.EndPos + 1);
}
}
next = next.left ?? next.right;
for (; next == null; item = item.Parent)
{
int top = rootTop + 2 * level;
Print(item.Text, top, item.StartPos);
if (item.Left != null)
{
Print("/", top + 1, item.Left.EndPos);
Print("_", top, item.Left.EndPos + 1, item.StartPos);
}
if (item.Right != null)
{
Print("_", top, item.EndPos, item.Right.StartPos - 1);
Print("\\", top + 1, item.Right.StartPos - 1);
}
if (--level < 0) break;
if (item == item.Parent.Left)
{
item.Parent.StartPos = item.EndPos + 1;
next = item.Parent.Node.right;
}
else
{
if (item.Parent.Left == null)
item.Parent.EndPos = item.StartPos - 1;
else
item.Parent.StartPos += (item.StartPos - 1 - item.Parent.EndPos) / 2;
}
}
}
Console.SetCursorPosition(0, rootTop + 2 * last.Count - 1);
}
private static void Print(string s, int top, int left, int right = -1)
{
Console.SetCursorPosition(left, top);
if (right < 0) right = left + s.Length;
while (Console.CursorLeft < right) Console.Write(s);
}
}
As you can see, I've added some parameters that affect the formatting. By default it produces the most compact representation.
In order to play with it, I've modified the BTree class as follows:
public class BTree
{
// ...
public BNode Root { get { return _root; } }
public void Print()
{
Root.Print();
}
}
Using your sample data, here are some results:
btr.Root.Print();
btr.Root.Print(textFormat: "(0)", spacing: 2);
UPDATE: IMO the default format above is compact and readable, but just for fun, adjusted the algorithm to produce more "graphical" output (textFormat and spacing parameters removed):
public static class BTreePrinter
{
class NodeInfo
{
public BNode Node;
public string Text;
public int StartPos;
public int Size { get { return Text.Length; } }
public int EndPos { get { return StartPos + Size; } set { StartPos = value - Size; } }
public NodeInfo Parent, Left, Right;
}
public static void Print(this BNode root, int topMargin = 2, int leftMargin = 2)
{
if (root == null) return;
int rootTop = Console.CursorTop + topMargin;
var last = new List<NodeInfo>();
var next = root;
for (int level = 0; next != null; level++)
{
var item = new NodeInfo { Node = next, Text = next.item.ToString(" 0 ") };
if (level < last.Count)
{
item.StartPos = last[level].EndPos + 1;
last[level] = item;
}
else
{
item.StartPos = leftMargin;
last.Add(item);
}
if (level > 0)
{
item.Parent = last[level - 1];
if (next == item.Parent.Node.left)
{
item.Parent.Left = item;
item.EndPos = Math.Max(item.EndPos, item.Parent.StartPos);
}
else
{
item.Parent.Right = item;
item.StartPos = Math.Max(item.StartPos, item.Parent.EndPos);
}
}
next = next.left ?? next.right;
for (; next == null; item = item.Parent)
{
Print(item, rootTop + 2 * level);
if (--level < 0) break;
if (item == item.Parent.Left)
{
item.Parent.StartPos = item.EndPos;
next = item.Parent.Node.right;
}
else
{
if (item.Parent.Left == null)
item.Parent.EndPos = item.StartPos;
else
item.Parent.StartPos += (item.StartPos - item.Parent.EndPos) / 2;
}
}
}
Console.SetCursorPosition(0, rootTop + 2 * last.Count - 1);
}
private static void Print(NodeInfo item, int top)
{
SwapColors();
Print(item.Text, top, item.StartPos);
SwapColors();
if (item.Left != null)
PrintLink(top + 1, "┌", "┘", item.Left.StartPos + item.Left.Size / 2, item.StartPos);
if (item.Right != null)
PrintLink(top + 1, "└", "┐", item.EndPos - 1, item.Right.StartPos + item.Right.Size / 2);
}
private static void PrintLink(int top, string start, string end, int startPos, int endPos)
{
Print(start, top, startPos);
Print("─", top, startPos + 1, endPos);
Print(end, top, endPos);
}
private static void Print(string s, int top, int left, int right = -1)
{
Console.SetCursorPosition(left, top);
if (right < 0) right = left + s.Length;
while (Console.CursorLeft < right) Console.Write(s);
}
private static void SwapColors()
{
var color = Console.ForegroundColor;
Console.ForegroundColor = Console.BackgroundColor;
Console.BackgroundColor = color;
}
}
and the result is:

This is my take at it:
I've added PrintPretty to BNode, and I've removed the second Print function you had in BTree.
(Edit: I made the tree more lisible by changing the original chars to draw the branches of the tree)
static void Main(string[] args)
{
BTree btr = new BTree();
btr.Add(6);
btr.Add(2);
btr.Add(3);
btr.Add(11);
btr.Add(30);
btr.Add(9);
btr.Add(13);
btr.Add(18);
btr.Print();
}
public class BNode
{
public int item;
public BNode right;
public BNode left;
public BNode(int item)
{
this.item = item;
}
public void PrintPretty(string indent, bool last)
{
Console.Write(indent);
if (last)
{
Console.Write("└─");
indent += " ";
}
else
{
Console.Write("├─");
indent += "| ";
}
Console.WriteLine(item);
var children = new List<BNode>();
if (this.left != null)
children.Add(this.left);
if (this.right != null)
children.Add(this.right);
for (int i = 0; i < children.Count; i++)
children[i].PrintPretty(indent, i == children.Count - 1);
}
}
public class BTree
{
private BNode _root;
private int _count;
private IComparer<int> _comparer = Comparer<int>.Default;
public BTree()
{
_root = null;
_count = 0;
}
public bool Add(int Item)
{
if (_root == null)
{
_root = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(_root, Item);
}
}
private bool Add_Sub(BNode Node, int Item)
{
if (_comparer.Compare(Node.item, Item) < 0)
{
if (Node.right == null)
{
Node.right = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(Node.right, Item);
}
}
else if (_comparer.Compare(Node.item, Item) > 0)
{
if (Node.left == null)
{
Node.left = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(Node.left, Item);
}
}
else
{
return false;
}
}
public void Print()
{
_root.PrintPretty("", true);
}
}
This is the result (more compact, as I mentioned):
Edit: the following code has been modified in order to show the info about left-right:
static void Main(string[] args)
{
BTree btr = new BTree();
btr.Add(6);
btr.Add(2);
btr.Add(3);
btr.Add(11);
btr.Add(30);
btr.Add(9);
btr.Add(13);
btr.Add(18);
btr.Print();
}
public enum NodePosition
{
left,
right,
center
}
public class BNode
{
public int item;
public BNode right;
public BNode left;
public BNode(int item)
{
this.item = item;
}
private void PrintValue(string value, NodePosition nodePostion)
{
switch (nodePostion)
{
case NodePosition.left:
PrintLeftValue(value);
break;
case NodePosition.right:
PrintRightValue(value);
break;
case NodePosition.center:
Console.WriteLine(value);
break;
default:
throw new NotImplementedException();
}
}
private void PrintLeftValue(string value)
{
Console.ForegroundColor = ConsoleColor.Magenta;
Console.Write("L:");
Console.ForegroundColor = (value == "-") ? ConsoleColor.Red : ConsoleColor.Gray;
Console.WriteLine(value);
Console.ForegroundColor = ConsoleColor.Gray;
}
private void PrintRightValue(string value)
{
Console.ForegroundColor = ConsoleColor.Green;
Console.Write("R:");
Console.ForegroundColor = (value == "-") ? ConsoleColor.Red : ConsoleColor.Gray;
Console.WriteLine(value);
Console.ForegroundColor = ConsoleColor.Gray;
}
public void PrintPretty(string indent, NodePosition nodePosition, bool last, bool empty)
{
Console.Write(indent);
if (last)
{
Console.Write("└─");
indent += " ";
}
else
{
Console.Write("├─");
indent += "| ";
}
var stringValue = empty ? "-" : item.ToString();
PrintValue(stringValue, nodePosition);
if(!empty && (this.left != null || this.right != null))
{
if (this.left != null)
this.left.PrintPretty(indent, NodePosition.left, false, false);
else
PrintPretty(indent, NodePosition.left, false, true);
if (this.right != null)
this.right.PrintPretty(indent, NodePosition.right, true, false);
else
PrintPretty(indent, NodePosition.right, true, true);
}
}
}
public class BTree
{
private BNode _root;
private int _count;
private IComparer<int> _comparer = Comparer<int>.Default;
public BTree()
{
_root = null;
_count = 0;
}
public bool Add(int Item)
{
if (_root == null)
{
_root = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(_root, Item);
}
}
private bool Add_Sub(BNode Node, int Item)
{
if (_comparer.Compare(Node.item, Item) < 0)
{
if (Node.right == null)
{
Node.right = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(Node.right, Item);
}
}
else if (_comparer.Compare(Node.item, Item) > 0)
{
if (Node.left == null)
{
Node.left = new BNode(Item);
_count++;
return true;
}
else
{
return Add_Sub(Node.left, Item);
}
}
else
{
return false;
}
}
public void Print()
{
_root.PrintPretty("", NodePosition.center, true, false);
}
}
The result:

If your tree is in the form of a QuickGraph IBidirectionalGraph, you could print it recursively like this:
static void PrintVertex<TVertex>(IBidirectionalGraph<TVertex, IEdge<TVertex>> graph, TVertex vertex, Func<TVertex, string> labelSelector, bool[] isLastVertexIntendations = null)
{
var prefix = string.Concat(Enumerable.Concat(
/*up to last*/isLastVertexIntendations.NeverNull().Reverse().Skip(1).Reverse().Select(isLast => isLast ? " " : "│ "),
/*last*/isLastVertexIntendations.NeverNull().Reverse().Take(1).Select(isLast => isLast ? "└─" : "├─")
));
Console.Write(prefix);
Console.WriteLine(labelSelector(vertex));
var edges = graph.OutEdges(vertex);
foreach (var edge in edges)
{
PrintVertex(graph, edge.Target, labelSelector, isLastVertexIntendations: isLastVertexIntendations.NeverNull().Concat(new[] { edge == edges.Last() }).ToArray());
}
}

Inserting Into a Generic Linked List

I'm having an issue inserting a new object into a linked list. I use a custom method called Insert that takes the object type and the index where it should be placed. However, when I insert the object, the list doesn't update. Any idea why?
The list:
GenericLinkedList<string> bet = new GenericLinkedList<string>();
bet.Add("a");
bet.Add("b");
bet.Add("c");
bet.Add("d");
//bet.Remove();
bet.Insert("x", 2);
The Generic Linked List Class:
public class GenericLinkedList<T> where T : IComparable<T>
{
public GenericLinkedList()
{
count = 0;
head = null;
}
#region Nested Node Class
private class Node<T>
{
private T data;
public T Data
{
get { return data; }
set { data = value; }
}
private Node<T> next;
public Node<T> Next
{
get { return next; }
set { next = value; }
}
public Node<T> Previous { get; set; }
public Node(T obj_t)
{
next = null;
data = obj_t;
}
public Node()
{
next = null;
}
}
#endregion
private Node<T> head;
private Node<T> tail;
private int count;
public int Count
{
get
{
int num;
if (count < 0)
num = 0;
else {
num = count;
}
return num;
}
}
}
The Insert Method:
public void Insert(T data, int index)
{
Node<T> replacedItem = new Node<T>();
Node<T> newItem = new Node<T>(data);
if (head == null)
{
head = new Node<T>(data);
tail = head;
}
else
{
Node<T> current = head;
Node<T> tempNode = new Node<T>();
if (index > 0 && index <= count + 1)
{
int c = 0;
while (current != null)
{
if (c == index)
{
tempNode = current;
current = newItem;
current.Next = tempNode;
}
else
{
current = current.Next;
}
c++;
}
}
count++;
}
}
The Add Method:
public void Add(T data)
{
count++;
if (head == null)
{
head = new Node<T>(data);
tail = head;
}
else
{
tail.Next = new Node<T>(data);
tail.Next.Previous = tail;
tail = tail.Next;
}
}

Need to add count++ in case head is null. Also count++ should go inside if(index>0&&index<=count+1)
public void Insert(T data, int index)
{
Node<T> replacedItem = new Node<T>();
Node<T> newItem = new Node<T>(data);
if (head == null)
{
head = new Node<T>(data);
tail = head;
count++;
}
else
{
Node<T> current = head;
Node<T> tempNode = new Node<T>();
if (index > 0 && index <= count + 1)
{
int c = 0;
while (current != null)
{
if (c == index)
{
tempNode = current;
current = newItem;
current.Next = tempNode;
}
else
{
current = current.Next;
}
c++;
}
count++;
}
}
}
See if this helps.

You not correctly add new item in your Insert method
in this place
tempNode = current; // save pointer to current item
current = newItem; // save in current new item
current.Next = tempNode; //set next to counter
but you don't change link from previous element, so when you again go from head you just miss your added item.
You need change this code something like
public void Insert(T data, int index)
{
Node<T> replacedItem = new Node<T>();
Node<T> newItem = new Node<T>(data);
if (head == null)
{
head = new Node<T>(data);
tail = head;
count++;
}
else
{
Node<T> current = head;
Node<T> tempNode = new Node<T>();
if (index > 0 && index <= count + 1)
{
int c = 0;
while (current != null)
{
if (c == index)
{
tempNode = current;
current = newItem;
//update link from previous element
if(tempNode.Previous != null)
tempNode.Previous.Next = current;
current.Next = tempNode;
current.Previous = tempNode.Previous;
tempNode.Previous = current;
count++;
break;
}
else
{
current = current.Next;
}
c++;
}
}
}
}

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.

Creating A Linked List. C# - c#

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Inserting Into a Generic Linked List

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