binary search tree in C++ code example

Example 1: binary search tree in cpp using class

/* Program to implement Binary Search Tree in c++ using classes  */
#include<iostream>
#include<stdlib.h>
#include<cstdlib>
using namespace std;

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

class BinaryTree {
    private:
        struct Node* root;
    public:
        BinaryTree() {
            root = NULL;
        }
        Node* createNode(int);
        Node* insertNode(Node*, int);
        Node* deleteNode(Node*, int);
        void inOrder(Node*);
        void preOrder(Node*);
        void postOrder(Node*);
        Node* findMinimum(Node*);

        Node* getRoot() {
            return root;
        }

        void setRoot(Node* ptr) {
            root = ptr; 
        }
};

Node* BinaryTree :: createNode(int n) {
    Node* newNode = new struct Node();
    newNode->data = n;
    newNode->left = NULL;
    newNode->right = NULL;
    return newNode; 
}


Node* BinaryTree :: findMinimum(Node* rootPtr) {
    while(rootPtr->left != NULL) {
        rootPtr = rootPtr->left;
    }
    return rootPtr;
}


Node* BinaryTree :: insertNode(Node* rootPtr, int n) {
    if(rootPtr == NULL) {
        return createNode(n);
    }
    if(n < rootPtr->data) {
        rootPtr->left = insertNode(rootPtr->left, n);
    }
    if(n > rootPtr->data) {
        rootPtr->right = insertNode(rootPtr->right, n);
    }
    return rootPtr;
}


Node* BinaryTree :: deleteNode(Node* rootPtr, int n) {
    if(rootPtr == NULL) {
        cout<<"Node to be deleted is not present.!"<<endl;
        return rootPtr;
    }
    else if(n < rootPtr->data) {
        rootPtr->left = deleteNode(rootPtr->left, n);
    } else if(n > rootPtr->data) {
        rootPtr->right = deleteNode(rootPtr->right, n);
    } else {
        if(rootPtr->left == NULL && rootPtr->right == NULL) {
            delete rootPtr;
            rootPtr = NULL;
        }
        else if(root->left == NULL) {
            struct Node* temp = rootPtr;
            rootPtr = rootPtr->right;
            delete temp;
        }
        else if(rootPtr->right == NULL) {
            struct Node* temp = rootPtr;
            rootPtr = rootPtr->left;
            delete temp;
        } else {
            Node* temp = findMinimum(rootPtr->right);
            rootPtr->data = temp->data;
            rootPtr->left = deleteNode(rootPtr->right, temp->data);
        }
    }

    return rootPtr;
}


void BinaryTree :: inOrder(Node* root) {
    if(root == NULL) {
        return;
    }
    inOrder(root->left);
    cout<<root->data<<"\t";
    inOrder(root->right);
}

void BinaryTree :: preOrder(Node* root) {
    if(root == NULL) return;
    cout<<root->data<<"\t";
    preOrder(root->left);
    preOrder(root->right);
}

void BinaryTree :: postOrder(Node* root) {
    if(root == NULL) return;
    postOrder(root->left);
    postOrder(root->right);
    cout<<root->data<<"\t";
}

int main() {
    BinaryTree l1;
    int ch, ele, res;
    Node* ptr;
    do {
            cout<<"1 - Insert Node\n";
            cout<<"2 - IN-ORDER Traversal\n";
            cout<<"3 - PRE-ORDER Traversal\n";
            cout<<"4 - POST-ORDER Traversal\n";
            cout<<"Enter choice\n";
            cin>>ch;
            switch(ch) {
                case 1: 
                    cout<<"Entre element to insert to the List\n";
                    cin>>ele;

                    ptr = l1.insertNode(l1.getRoot(), ele);
  
                    l1.setRoot(ptr);
                    break;
                case 2:
                    cout<<"---IN-ORDER TRAVERSAL---"<<endl;
                    l1.inOrder(l1.getRoot());
                    cout<<endl;
                    break;
                case 3:
                    cout<<"---PRE-ORDER TRAVERSAL---"<<endl;
                    l1.preOrder(l1.getRoot());
                    cout<<endl;
                    break;
                case 4:
                    cout<<"---POST-ORDER TRAVERSAL---"<<endl;
                    l1.postOrder(l1.getRoot());
                    cout<<endl;
                    break;
                case 5:
                    cout<<"Enter node to be deleted."<<endl;
                    cin>>ele;
                    ptr = l1.deleteNode(l1.getRoot(), ele);
                    l1.setRoot(ptr);
                default: cout<<"Invalid choice"<<endl;
            }
    } while(ch >=1 && ch <= 5);
    return 0;
}

Example 2: binary tree search

/* This is just the seaching function you need to write the required code.
	Thank you. */

void searchNode(Node *root, int data)
{
    if(root == NULL)
    {
        cout << "Tree is empty\n";
        return;
    }

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

    while(!q.empty())
    {
        Node *temp = q.front();
        q.pop();

        if(temp->data == data)
        {
            cout << "Node found\n";
            return;
        }

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

    cout << "Node not found\n";
}

Example 3: binary search tree

Binary Search Tree is a node-based binary tree data structure which has the following properties:

The left subtree of a node contains only nodes with keys lesser than the node’s key.
The right subtree of a node contains only nodes with keys greater than the node’s key.
The left and right subtree each must also be a binary search tree.

Example 4: binary search tree

# Driver Code 
arr = [ 2, 3, 4, 10, 40 ] 
x = 10
  
# Function call 
result = binarySearch(arr, 0, len(arr)-1, x) 
  
if result != -1: 
    print ("Element is present at index % d" % result) 
else: 
    print ("Element is not present in array")

Example 5: insert binary search tree

void BSNode::insert(std::string value) {

	if (this->_data == value) {
		_count++;
		return;
	}

	if (this->_data > value) {
		if (this->getLeft() == nullptr) {
			this->_left = new BSNode(value);
		}
		this->getLeft()->insert(value);
		return;
	}

	if (this->getRight() == nullptr) {
		this->_right = new BSNode(value);
		return;
	}
	this->getRight()->insert(value);
}