Hello everybody!
I have written a code in C# for the implementation of AVL_trees. I am having some problems with nodes that's why I am unable to insert data in the nodes. Below is my whole code.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.ServiceModel;
namespace DataProject
{
/// <summary>
/// Interaction logic for Student_database.xaml
/// </summary>
///
public class Studentdb
{
public int student_id;
public char[] Student_name=new char[20];
public char[] dob=new char[10];
public char gender;
public char[] department=new char[5];
}
public class avl_node:Studentdb
{
public Studentdb data;
public avl_node left;
public avl_node right;
public int height;
}
public class avl_methods : avl_node
{
public int Height(avl_node a_node)
{
a_node = new avl_node();
if (a_node == null)
{
return -1;
}
else
{
return a_node.height;
}
}
public avl_node insert(Studentdb x, avl_node T)
{
if(T==null)
{
T = new avl_node();
T.data = x;
T.left = T.right = null;
T.height = 0;
}
else if(x.student_id<T.student_id)
{
T.left=insert(x,T.left);
if ((Height(T.left) - Height(T.right)) == 2)
{
if (x.student_id < T.left.student_id)
{
SingleRotateWithLeft(T);
}
else
{
DoubleRotateWithLeft(T);
}
}
}
else if(x.student_id>T.student_id)
{
T.right = insert(x, T.right);
if ((Height(T.right) - Height(T.left)) == 2)
{
if (x.student_id > T.right.student_id)
{
SingleRotateWithRight(T);
}
else
{
DoubleRotateWithRight(T);
}
}
}
return T;
}
public avl_node SingleRotateWithLeft(avl_node k2)
{
avl_node k1;
k1 = k2.left;
k2.left = k1.right;
k1.right = k2;
k2.height = max(Height(k2.left), Height(k2.right)) + 1;
k1.height = max(Height(k1.left), k2.height) + 1;
return k1;
}
public avl_node SingleRotateWithRight(avl_node k1)
{
avl_node k2;
k2 = k1.right;
k1.right = k2.left;
k2.left = k1;
k1.height = max(Height(k1.left), Height(k1.right)) + 1;
k2.height = max(k1.height, Height(k2.right)) + 1;
return k2;
}
public avl_node DoubleRotateWithLeft(avl_node k3)
{
k3.left = SingleRotateWithRight(k3.left);
return (SingleRotateWithLeft(k3));
}
public avl_node DoubleRotateWithRight(avl_node k1)
{
k1.right = SingleRotateWithLeft( k1.right );
return (SingleRotateWithRight(k1));
}
public avl_node Search(int x,avl_node T)
{
if (T == null)
{
return null;
}
if (x < T.student_id)
{
return (Search(x, T.left));
}
else if (x > T.student_id)
{
return (Search(x, T.right));
}
else
{
return T;
}
}
public avl_node Delete(Studentdb x, avl_node T)
{
avl_node tmp_cell;
avl_node child= new avl_node();
if (T==null)
{
MessageBox.Show("Element not found!", "Alert", MessageBoxButton.OK, MessageBoxImage.Exclamation);
}
else if(x.student_id < T.student_id)
{
T.left = Delete(x, T.left);
}
else if(x.student_id > T.student_id)
{
T.right = Delete(x, T.right);
}
else
if (Convert.ToBoolean(T.left.student_id) && Convert.ToBoolean(T.right.student_id))
{
tmp_cell = find_min(T.right);
T.data = tmp_cell.data;
T.right = Delete(T.data, T.right);
}
else
{
tmp_cell = T;
if (T.left == null)
child = T.right;
if (T.right == null)
child = T.left;
int a = Convert.ToInt32(tmp_cell);
GC.Collect(a);
return child;
}
return T;
}
public int max(int a, int b)
{
if(a>b)
{
return a;
}
else
{
return b;
}
}
public int min(int a, int b)
{
if (a<b)
{
return b;
}
else
{
return a;
}
}
public avl_node find_min(avl_node T)
{
if(T==null)
{
return null;
}
else if(T.left==null)
{
return T;
}
else
{
return (find_min(T.left));
}
}
public avl_node find_max(avl_node T)
{
if (T == null)
{
return null;
}
else if (T.right == null)
{
return T;
}
else
{
return (find_min(T.right));
}
}
}
public partial class Student_database : Window
{
private MainWindow m_parent;
public void Login(MainWindow parent)
{
m_parent = parent;
return;
}
private void Success() //Show the new Window
{
m_parent.Show();
}
public Student_database()
{
InitializeComponent();
}
public avl_node root;
public void AVLroot()
{
root.data = null;
root.left = null;
root.right = null;
root.height = 0;
}
private void button1_Click(object sender, RoutedEventArgs e)
{
Studentdb stdb = new Studentdb();
char[] arr;
stdb.student_id =Convert.ToInt32(textBox1.Text);
arr= textBox2.Text.ToCharArray();
stdb.Student_name = arr;
arr= textBox3.Text.ToCharArray();
stdb.dob = arr;
stdb.gender = Convert.ToChar(textBox4.Text);
arr = textBox5.Text.ToCharArray();
stdb.department = arr;
avl_methods avlm = new avl_methods();
avl_node a=avlm.insert(stdb,root);
textBox1.Clear();
textBox2.Clear();
textBox3.Clear();
textBox4.Clear();
textBox5.Clear();
MessageBox.Show(String.Format("{0}",a.gender));
}
private void button2_Click(object sender, RoutedEventArgs e)
{
Studentdb stdb = new Studentdb();
avl_methods avlm = new avl_methods();
int a = Convert.ToInt32(textBox6.Text);
avl_node avln = avlm.Search(a, root);
if (avln.data.student_id == a)
{
MessageBox.Show("hi");
//textBox1.Text = avln.student_id.ToString();
//textBox2.Text = avln.Student_name.ToString();
//textBox3.Text = avln.gender.ToString();
//textBox4.Text = avln.dob.ToString();
//textBox5.Text = avln.department.ToString();
}
}
}
}
When I am inserting a node in the insert function, I am receiving a node in return from the function. I have stored it in variable 'a' having the data type avl_node, then I used the messagebox to view an item from that node. (The purpose of all this was to check whether my data entered correctly or not but, nothing is viewed...All I can see is an empty messagebox)....
Hoping for a better response!
Regards
Umer