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BinaryTree.cs
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BinaryTree.cs
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using static BT;
//table Row for Binary Tree Table
class BinaryTreeTableRow
{
public int? Key { get; set; }
public BinaryTreeTableRow()
{
Key = null;
}
}
class BinaryTree
{
private BinaryTreeTableRow[] HashTable { get; set; }
private int ModValue;
//fills all table rows as null
public BinaryTree(int modValue)
{
ModValue = modValue;
HashTable = new BinaryTreeTableRow[modValue];
for (int i = 0; i < modValue; i++)
{
HashTable[i] = new BinaryTreeTableRow();
}
}
//hash function
private int Hash(int key)
{
return key % ModValue;
}
//quotient function, if key is smaller than mod value, it returns key to prevent infinite loop
private int Quotient(int key)
{
if (key < ModValue)
{
return key;
}
else
{
return key / ModValue % ModValue;
}
}
//inserts key to table
public void Insert(int key)
{
int hashedIndex = Hash(key);
//if hashed index is empty, insert key
if (HashTable[hashedIndex].Key == null)
{
HashTable[hashedIndex].Key = key;
return;
}
//if hashed index is not empty, find space for key
else
{
//create tree that uses for insertion in binary tree method
//get the path between root and first found empty node
BT tree = new BT(ModValue);
List<BTNode> path = tree.CreateTree(HashTable, key);
path.Reverse();
int tempMovedKey = key;
int tempMovedIndex = path[0].Index.Value;
//move the keys that needed to move
int i = 0;
while (i < path.Count - 1)
{
if (path[i].IsMove.Value)
{
HashTable[tempMovedIndex].Key = HashTable[path[i + 1].Index.Value].Key;
tempMovedIndex = path[i + 1].Index.Value;
}
else
{
tempMovedIndex = path[i].Index.Value;
while (path[i + 1].IsMove != null)
{
if (path[i + 1].IsMove.Value)
{
HashTable[tempMovedIndex].Key = HashTable[path[i + 1].Index.Value].Key;
break;
}
i++;
}
}
i++;
}
HashTable[tempMovedIndex].Key = tempMovedKey;
}
}
//returns index of key (with Linear Quotient method)
private int GetIndex(int key)
{
int hashedIndex = Hash(key);
if (HashTable[hashedIndex].Key == null)
{
return -1;
}
else if (HashTable[hashedIndex].Key == key)
{
return hashedIndex;
}
else
{
int quotient = Quotient(key);
int pointer = (hashedIndex + quotient) % ModValue;
while (pointer != hashedIndex)
{
if (HashTable[pointer].Key == null)
{
pointer = (pointer + quotient) % ModValue;
}
else
{
if (HashTable[pointer].Key.Value == key)
{
return pointer;
}
pointer = (pointer + quotient) % ModValue;
}
}
}
return -1;
}
//searches key in table
public void Search(int key)
{
int index = GetIndex(key);
if (index != -1)
{
Console.WriteLine("Key {0} is found on index {1}", key, index);
return;
}
Console.WriteLine("Key {0} is not found", key);
}
//returns number of probes for key (with Linear Quotient method)
public int GetProb(int key)
{
int hashedIndex = Hash(key);
if (HashTable[hashedIndex].Key == null)
{
return 0;
}
else if (HashTable[hashedIndex].Key == key)
{
return 1;
}
else
{
int count = 1;
int quotient = Quotient(key);
int pointer = (hashedIndex + quotient) % ModValue;
while (pointer != hashedIndex)
{
if (HashTable[pointer].Key == null)
{
count++;
pointer = (pointer + quotient) % ModValue;
}
else
{
count++;
if (HashTable[pointer].Key.Value == key)
{
return count;
}
pointer = (pointer + quotient) % ModValue;
}
}
}
return 0;
}
//returns average number of probes for all keys
public double AverageProbes(List<int> insertNumbers)
{
double totalProbes = 0;
foreach (var item in insertNumbers)
{
totalProbes += GetProb(item);
}
return totalProbes / insertNumbers.Count;
}
//prints table
public void Print()
{
Console.WriteLine("--Binary Tree--");
string row = string.Format("{0,0}{1,8}", "Index", "Key");
Console.WriteLine(row);
for (int i = 0; i < HashTable.Length; i++)
{
row = string.Format("{0,3}{1,10}", i, HashTable[i].Key);
Console.WriteLine(row);
}
}
}
//Binary Tree class for tree creation to insert key when collision occurs
class BT
{
//Node class for Binary Tree
public class BTNode
{
public int? Index;
public BTNode Left, Right, Parent;
public bool? IsMove;
public BTNode()
{
Index = null;
Left = Right = Parent = null;
IsMove = null;
}
}
public BTNode Root;
public int ModValue;
public BT(int modValue)
{
Root = null;
ModValue = modValue;
}
private int Quotient(int key)
{
if (key<ModValue)
{
return key;
}
else
{
return key / ModValue % ModValue;
}
}
//inserts node to the binary tree with Breadth First approach
//inserts according to rules of binary tree hashing method
//returns null if the node that inserted is not empty
//return itself if the node that inserted is empty
private BTNode InsertNode(BinaryTreeTableRow[] table, int key)
{
if (Root == null)
{
Root = new BTNode();
Root.Index = key % ModValue;
if (table[key % ModValue].Key == null)
{
return Root;
}
return null;
}
Queue<BTNode> queue = new Queue<BTNode>();
queue.Enqueue(Root);
while (queue.Count > 0)
{
BTNode temp = queue.Dequeue();
if (temp.Left == null)
{
temp.Left = new BTNode();
temp.Left.Parent = temp;
temp.Left.IsMove = false;
BTNode iterator = temp.Left;
bool isAllLeft = true;
while (iterator.Parent.IsMove != null)
{
if (iterator.Parent.IsMove == true)
{
isAllLeft = false;
break;
}
iterator = iterator.Parent;
}
int tempQuotient;
if (isAllLeft)
{
tempQuotient = Quotient(key);
}
else
{
while (iterator.Parent.IsMove != null)
{
if (iterator.Parent.IsMove.Value)
{
iterator = iterator.Parent;
break;
}
iterator = iterator.Parent;
}
tempQuotient = Quotient(table[iterator.Parent.Index.Value].Key.Value);
}
temp.Left.Index = (tempQuotient + temp.Index) % ModValue;
if (table[temp.Left.Index.Value].Key == null)
{
return temp.Left;
}
break;
}
else
{
queue.Enqueue(temp.Left);
}
if (temp.Right == null)
{
temp.Right = new BTNode();
temp.Right.Parent = temp;
temp.Right.IsMove = true;
int tempQuotient = Quotient(table[temp.Index.Value].Key.Value);
temp.Right.Index = (tempQuotient + temp.Index) % ModValue;
if (table[temp.Right.Index.Value].Key == null)
{
return temp.Right;
}
break;
}
else
{
queue.Enqueue(temp.Right);
}
}
return null;
}
//create tree and return the path between root and last inserted node
public List<BTNode> CreateTree(BinaryTreeTableRow[] table, int data)
{
BTNode lastNode = InsertNode(table, data);
while (lastNode == null)
{
lastNode = InsertNode(table, data);
}
List<BTNode> path = FindPath(lastNode.Index.Value);
return path;
}
//finds path between root and target node
private List<BTNode> FindPath(int target)
{
List<BTNode> path = new List<BTNode>();
FindPathRecursive(Root, target, path);
return path;
}
//helper function for FindPath
private bool FindPathRecursive(BTNode current, int target, List<BTNode> path)
{
if (current == null)
{
return false;
}
path.Add(current);
if (current.Index == target)
{
return true;
}
if (FindPathRecursive(current.Left, target, path) || FindPathRecursive(current.Right, target, path))
{
return true;
}
path.RemoveAt(path.Count - 1);
return false;
}
}