tugas 4 program red-back

/** C++ implementation for Red-Black Tree Insertion
This code is adopted from the code provided by
Dinesh Khandelwal in comments **/
#include <bits/stdc++.h>
using namespace std;

enum Color {RED, BLACK};

struct Node
{
int data;
bool color;
Node *left, *right, *parent;

// Constructor
Node(int data)
{
this->data = data;
left = right = parent = NULL;
this->color = RED;
}
};

// Class to represent Red-Black Tree
class RBTree
{
private:
Node *root;
protected:
void rotateLeft(Node *&, Node *&);
void rotateRight(Node *&, Node *&);
void fixViolation(Node *&, Node *&);
public:
// Constructor
RBTree() { root = NULL; }
void insert(const int &n);
void inorder();
void levelOrder();
};

// A recursive function to do level order traversal
void inorderHelper(Node *root)
{
if (root == NULL)
return;

inorderHelper(root->left);
cout << root->data << " ";
inorderHelper(root->right);
}

/* A utility function to insert a new node with given key
in BST */
Node* BSTInsert(Node* root, Node *pt)
{
/* If the tree is empty, return a new node */
if (root == NULL)
return pt;

/* Otherwise, recur down the tree */
if (pt->data < root->data)
{
root->left = BSTInsert(root->left, pt);
root->left->parent = root;
}
else if (pt->data > root->data)
{
root->right = BSTInsert(root->right, pt);
root->right->parent = root;
}

/* return the (unchanged) node pointer */
return root;
}

// Utility function to do level order traversal
void levelOrderHelper(Node *root)
{
if (root == NULL)
return;

std::queue<Node *> q;
q.push(root);

while (!q.empty())
{
Node *temp = q.front();
cout << temp->data << " ";
q.pop();

if (temp->left != NULL)
q.push(temp->left);

if (temp->right != NULL)
q.push(temp->right);
}
}

void RBTree::rotateLeft(Node *&root, Node *&pt)
{
Node *pt_right = pt->right;

pt->right = pt_right->left;

if (pt->right != NULL)
pt->right->parent = pt;

pt_right->parent = pt->parent;

if (pt->parent == NULL)
root = pt_right;

else if (pt == pt->parent->left)
pt->parent->left = pt_right;

else
pt->parent->right = pt_right;

pt_right->left = pt;
pt->parent = pt_right;
}

void RBTree::rotateRight(Node *&root, Node *&pt)
{
Node *pt_left = pt->left;

pt->left = pt_left->right;

if (pt->left != NULL)
pt->left->parent = pt;

pt_left->parent = pt->parent;

if (pt->parent == NULL)
root = pt_left;

else if (pt == pt->parent->left)
pt->parent->left = pt_left;

else
pt->parent->right = pt_left;

pt_left->right = pt;
pt->parent = pt_left;
}

// This function fixes violations caused by BST insertion
void RBTree::fixViolation(Node *&root, Node *&pt)
{
Node *parent_pt = NULL;
Node *grand_parent_pt = NULL;

while ((pt != root) && (pt->color != BLACK) &&
(pt->parent->color == RED))
{

parent_pt = pt->parent;
grand_parent_pt = pt->parent->parent;

/* Case : A
Parent of pt is left child of Grand-parent of pt */
if (parent_pt == grand_parent_pt->left)
{

Node *uncle_pt = grand_parent_pt->right;

/* Case : 1
The uncle of pt is also red
Only Recoloring required */
if (uncle_pt != NULL && uncle_pt->color == RED)
{
grand_parent_pt->color = RED;
parent_pt->color = BLACK;
uncle_pt->color = BLACK;
pt = grand_parent_pt;
}

else
{
/* Case : 2
pt is right child of its parent
Left-rotation required */
if (pt == parent_pt->right)
{
rotateLeft(root, parent_pt);
pt = parent_pt;
parent_pt = pt->parent;
}

/* Case : 3
pt is left child of its parent
Right-rotation required */
rotateRight(root, grand_parent_pt);
swap(parent_pt->color, grand_parent_pt->color);
pt = parent_pt;
}
}

/* Case : B
Parent of pt is right child of Grand-parent of pt */
else
{
Node *uncle_pt = grand_parent_pt->left;

/* Case : 1
The uncle of pt is also red
Only Recoloring required */
if ((uncle_pt != NULL) && (uncle_pt->color == RED))
{
grand_parent_pt->color = RED;
parent_pt->color = BLACK;
uncle_pt->color = BLACK;
pt = grand_parent_pt;
}
else
{
/* Case : 2
pt is left child of its parent
Right-rotation required */
if (pt == parent_pt->left)
{
rotateRight(root, parent_pt);
pt = parent_pt;
parent_pt = pt->parent;
}

/* Case : 3
pt is right child of its parent
Left-rotation required */
rotateLeft(root, grand_parent_pt);
swap(parent_pt->color, grand_parent_pt->color);
pt = parent_pt;
}
}
}

root->color = BLACK;
}

// Function to insert a new node with given data
void RBTree::insert(const int &data)
{
Node *pt = new Node(data);

// Do a normal BST insert
root = BSTInsert(root, pt);

// fix Red Black Tree violations
fixViolation(root, pt);
}

// Function to do inorder and level order traversals
void RBTree::inorder() { inorderHelper(root);}
void RBTree::levelOrder() { levelOrderHelper(root); }

// Driver Code
int main()
{
RBTree tree;

tree.insert(7);
tree.insert(6);
tree.insert(5);
tree.insert(4);
tree.insert(3);
tree.insert(2);
tree.insert(1);

cout<<"DANDY ALFIANTO 41119189\n"<<endl;

cout << "Inoder Traversal of Created Tree\n";
tree.inorder();

cout << "\n\nLevel Order Traversal of Created Tree\n";
tree.levelOrder();

return 0;
}

referensi :

https://www.geeksforgeeks.org/c-program-red-black-tree-insertion/

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