Saturday, 6 February 2016

BST C++ | Binary Search Tree C++ | Binary Search Tree in Data Structure

BST C++ | Binary Search Tree C++ | Binary Search Tree in Data Structure
Description:    The following C++ Binary Search Tree code includes these functions of the Binary Search Trees:
  1. Default Constructor
  2. Parameterized Constructor
  3. Copy Constructor
  4. Copy Tree
  5. Search
  6. Insert
  7. Delete
  8. Print
    • Pre-order traversal
    • In-order traversal
    • Post-order traversal
  9. Check Equivalence
  10. Destructor 

Download Binary Search Tree C++


 C++ Code

#include <iostream>
using namespace std;

struct Node_Tree {
    int data;
    Node_Tree *left;
    Node_Tree *right;
};

struct Node_Queue {
    Node_Tree *data_Node;
    Node_Queue *next;
};

class Queue {

    Node_Queue dummyHead;       //Dummy head Node_Queue
    Node_Queue *tail;
    int no_of_elements;

public:
    Queue() {
       dummyHead.next = nullptr;
       tail = &dummyHead;
       no_of_elements = 0;
    }

    bool isEmpty() {
       return (dummyHead.next == nullptr);
    }

    bool enqueue(Node_Tree *obj) {
       Node_Queue *temp = new Node_Queue;
       temp->data_Node = obj;
       temp->next = nullptr;
       tail->next = temp;
       tail = temp;
       no_of_elements++;
       return true;
    }

    bool dequeue(Node_Tree *&n) {
       if (isEmpty())
           return false;
       else {
           Node_Queue *temp = dummyHead.next;
           if (temp == tail)
              tail = &dummyHead;
           n = temp->data_Node;
           dummyHead.next = temp->next;
           delete temp;
           return true;
       }
    }

    ~Queue() {
       Node_Tree *n;
       while (!isEmpty())
           dequeue(n);
       tail = nullptr;
    }
};

class BinarySearchTree {
    Node_Tree *root;

public:

    BinarySearchTree() {
       root = nullptr;
    }

    BinarySearchTree(int x) {
       Node_Tree *newNode = new Node_Tree;
       newNode->data = x;
       newNode->left = nullptr;
       newNode->right = nullptr;
       root = newNode;
    }

    BinarySearchTree(BinarySearchTree &obj) {
       root = copyTree(obj.root);
    }

    Node_Tree* copyTree(Node_Tree *n) {
       if (n == nullptr)
           return nullptr;
       Node_Tree *left = copyTree(n->left);
       Node_Tree *right = copyTree(n->right);
       Node_Tree *newNode = new Node_Tree;
       newNode->data = n->data;
       newNode->left = left;
       newNode->right = right;
       return newNode;
    }

    Node_Tree* search(int key) {
       Node_Tree *curr = root;
       while (curr != nullptr) {
           if (curr->data == key)
              return curr;
           else if (key<curr->data)
              curr = curr->left;
           else
              curr = curr->right;
       }
       return nullptr;
    }

    void insert(int n) {
       Node_Tree *newNode = new Node_Tree;
       newNode->data = n;
       newNode->left = nullptr;
       newNode->right = nullptr;

       if (root == nullptr)
           root = newNode;
       else {
           Node_Tree *curr = root;
           while (1) {
              if (n<curr->data)
                  if (curr->left == nullptr)
                     break;
                  else
                     curr = curr->left;
              else
                  if (curr->right == nullptr)
                     break;
                  else
                     curr = curr->right;
           }
           if (curr->left == nullptr)
              curr->left = newNode;
           else
              curr->right = newNode;
       }
    };

    bool deleteNode(int x) {
       Node_Tree *del = search(x);
       if (del == nullptr)
           return false;
       Node_Tree *curr = del;
       if (curr->right->left != nullptr) {
           curr = curr->right;
           while (curr->left->left != nullptr)
              curr = curr->left;
           del->data = curr->left->data;
           delete curr->left;
           curr->left = nullptr;
       }
       else {
           del->data = curr->right->data;
           delete curr->right;
           curr->right = nullptr;
       }
       return true;
    }

    void print_InOrder() {
       cout << "\t\t\tIn-Order Printing\n\n";
       recursion_printInOrder(root);
    }

    void recursion_printInOrder(Node_Tree *n) {
       if (n == nullptr)
           return;
       recursion_printInOrder(n->left);
       cout << n->data << endl;
       recursion_printInOrder(n->right);
    }

    void print_PreOrder() {
       cout << "\t\t\tPre-Order Printing\n\n";
       recursion_printPreOrder(root);
    }

    void recursion_printPreOrder(Node_Tree *n) {
       if (n == nullptr)
           return;
       cout << n->data << endl;
       recursion_printPreOrder(n->left);
       recursion_printPreOrder(n->right);
    }

    void print_PostOrder() {
       cout << "\t\t\tPost-Order Printing\n\n";
       recursion_printPostOrder(root);
    }

    void recursion_printPostOrder(Node_Tree *n) {
       if (n == nullptr)
           return;
       recursion_printPostOrder(n->left);
       recursion_printPostOrder(n->right);
       cout << n->data << endl;
    }

    void print_LevelOrder() {
       cout << "\t\t\tLevel-Order Printing\n\n";
       Queue obj;
       obj.enqueue(root);
       Node_Tree *curr;
       while (!obj.isEmpty()) {
           obj.dequeue(curr);
           cout << curr->data << endl;
           if (curr->left != nullptr)
              obj.enqueue(curr->left);
           if (curr->right != nullptr)
              obj.enqueue(curr->right);
       }
    }

    bool check_Equivalance(BinarySearchTree obj) {
       cout << "\t\t\tCHECKING EQUIVALANCE\n\n";
       if (recursion_checkEquivalance(this->root, obj.root))
           return true;
       else
           return false;
    }

    bool recursion_checkEquivalance(Node_Tree *n1, Node_Tree *n2) {
       if (n1->left == nullptr && n1->right == nullptr && n2->left == nullptr && n2->right == nullptr)
           return true;
       if ((n1->left == n1->right && n2->left != n2->right) || (n2->left == n2->right && n1->left != n1->right)) //here n1->left==n1->right means that both are nullptr
           return false;
       if (n1->data != n2->data)
           return false;
       if (!recursion_checkEquivalance(n1->left, n2->left))
           return false;
       if (!recursion_checkEquivalance(n1->right, n2->right))
           return false;
    }

    ~BinarySearchTree() {
       recursion_Destructor(root);
    }

    void recursion_Destructor(Node_Tree *n) {
       if (n->left == nullptr && n->right == nullptr) {
           delete n;
           n = nullptr;
           return;
       }
       if (n->left != nullptr)
           recursion_Destructor(n->left);
       if (n->right != nullptr)
           recursion_Destructor(n->right);
       delete n;
       n = nullptr;
    }

};

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