Implementation of Binary Tree

Below is the code for insertion, deletion and traversal of the binary tree:

C
#include <stdio.h>

// Node structure to define the structure of the node
typedef struct Node {
    int data;
    struct Node *left, *right;
} Node;

// Function to create a new node
Node* newNode(int val) {
    Node* temp = (Node*)malloc(sizeof(Node));
    temp->data = val;
    temp->left = temp->right = NULL;
    return temp;
}

// Function to insert nodes
Node* insert(Node* root, int data) {
    // If tree is empty, new node becomes the root
    if (root == NULL) {
        root = newNode(data);
        return root;
    }

    // Queue to traverse the tree and find the position to insert the node
    Node* queue[100];
    int front = 0, rear = 0;
    queue[rear++] = root;
    while (front != rear) {
        Node* temp = queue[front++];
        // Insert node as the left child of the parent node
        if (temp->left == NULL) {
            temp->left = newNode(data);
            break;
        }
        // If the left child is not null, push it to the queue
        else
            queue[rear++] = temp->left;
        // Insert node as the right child of parent node
        if (temp->right == NULL) {
            temp->right = newNode(data);
            break;
        }
        // If the right child is not null, push it to the queue
        else
            queue[rear++] = temp->right;
    }
    return root;
}

/* Function to delete the given deepest node (d_node) in binary tree */
void deletDeepest(Node* root, Node* d_node) {
    Node* queue[100];
    int front = 0, rear = 0;
    queue[rear++] = root;
    // Do level order traversal until last node
    Node* temp;
    while (front != rear) {
        temp = queue[front++];
        if (temp == d_node) {
            temp = NULL;
            free(d_node);
            return;
        }
        if (temp->right) {
            if (temp->right == d_node) {
                temp->right = NULL;
                free(d_node);
                return;
            } else
                queue[rear++] = temp->right;
        }
        if (temp->left) {
            if (temp->left == d_node) {
                temp->left = NULL;
                free(d_node);
                return;
            } else
                queue[rear++] = temp->left;
        }
    }
}

/* Function to delete element in binary tree */
Node* deletion(Node* root, int key) {
    if (!root)
        return NULL;
    if (root->left == NULL && root->right == NULL) {
        if (root->data == key)
            return NULL;
        else
            return root;
    }
    Node* queue[100];
    int front = 0, rear = 0;
    queue[rear++] = root;
    Node* temp;
    Node* key_node = NULL;
    // Do level order traversal to find deepest node (temp) and node to be deleted (key_node)
    while (front != rear) {
        temp = queue[front++];
        if (temp->data == key)
            key_node = temp;
        if (temp->left)
            queue[rear++] = temp->left;
        if (temp->right)
            queue[rear++] = temp->right;
    }
    if (key_node != NULL) {
        int x = temp->data;
        key_node->data = x;
        deletDeepest(root, temp);
    }
    return root;
}

// Inorder tree traversal (Left - Root - Right)
void inorderTraversal(Node* root) {
    if (!root)
        return;
    inorderTraversal(root->left);
    printf("%d ", root->data);
    inorderTraversal(root->right);
}

// Preorder tree traversal (Root - Left - Right)
void preorderTraversal(Node* root) {
    if (!root)
        return;
    printf("%d ", root->data);
    preorderTraversal(root->left);
    preorderTraversal(root->right);
}

// Postorder tree traversal (Left - Right - Root)
void postorderTraversal(Node* root) {
    if (root == NULL)
        return;
    postorderTraversal(root->left);
    postorderTraversal(root->right);
    printf("%d ", root->data);
}

// Function for Level order tree traversal
void levelorderTraversal(Node* root) {
    if (root == NULL)
        return;

    // Queue for level order traversal
    Node* queue[100];
    int front = 0, rear = 0;
    queue[rear++] = root;
    while (front != rear) {
        Node* temp = queue[front++];
        printf("%d ", temp->data);
        // Push left child in the queue
        if (temp->left)
            queue[rear++] = temp->left;
        // Push right child in the queue
        if (temp->right)
            queue[rear++] = temp->right;
    }
}

/* Driver function to check the above algorithm. */
int main() {
    Node* root = NULL;
    // Insertion of nodes
    root = insert(root, 10);
    root = insert(root, 20);
    root = insert(root, 30);
    root = insert(root, 40);

    printf("Preorder traversal: ");
    preorderTraversal(root);

    printf("\nInorder traversal: ");
    inorderTraversal(root);

    printf("\nPostorder traversal: ");
    postorderTraversal(root);

    printf("\nLevel order traversal: ");
    levelorderTraversal(root);

    // Delete the node with data = 20
    root = deletion(root, 20);

    printf("\nInorder traversal after deletion: ");
    inorderTraversal(root);

    return 0;
}
Java
import java.util.LinkedList;
import java.util.Queue;

// Node class to define the structure of the node
class Node {
    int data;
    Node left, right;
    // Parameterized Constructor
    Node(int val) {
        data = val;
        left = right = null;
    }
}

public class BinaryTree {
    // Function to insert nodes
    public static Node insert(Node root, int data) {
        // If tree is empty, new node becomes the root
        if (root == null) {
            root = new Node(data);
            return root;
        }
        // Queue to traverse the tree and find the position to
        // insert the node
        Queue<Node> q = new LinkedList<>();
        q.offer(root);
        while (!q.isEmpty()) {
            Node temp = q.poll();
            // Insert node as the left child of the parent node
            if (temp.left == null) {
                temp.left = new Node(data);
                break;
            }
            // If the left child is not null push it to the
            // queue
            else
                q.offer(temp.left);
            // Insert node as the right child of parent node
            if (temp.right == null) {
                temp.right = new Node(data);
                break;
            }
            // If the right child is not null push it to the
            // queue
            else
                q.offer(temp.right);
        }
        return root;
    }

    /* function to delete the given deepest node
    (d_node) in binary tree */
    public static void deletDeepest(Node root, Node d_node) {
        Queue<Node> q = new LinkedList<>();
        q.offer(root);
        // Do level order traversal until last node
        Node temp;
        while (!q.isEmpty()) {
            temp = q.poll();
            if (temp == d_node) {
                temp = null;
                d_node = null;
                return;
            }
            if (temp.right != null) {
                if (temp.right == d_node) {
                    temp.right = null;
                    d_node = null;
                    return;
                } else
                    q.offer(temp.right);
            }
            if (temp.left != null) {
                if (temp.left == d_node) {
                    temp.left = null;
                    d_node = null;
                    return;
                } else
                    q.offer(temp.left);
            }
        }
    }

    /* function to delete element in binary tree */
    public static Node deletion(Node root, int key) {
        if (root == null)
            return null;
        if (root.left == null && root.right == null) {
            if (root.data == key)
                return null;
            else
                return root;
        }
        Queue<Node> q = new LinkedList<>();
        q.offer(root);
        Node temp = new Node(0);
        Node key_node = null;
        // Do level order traversal to find deepest
        // node(temp) and node to be deleted (key_node)
        while (!q.isEmpty()) {
            temp = q.poll();
            if (temp.data == key)
                key_node = temp;
            if (temp.left != null)
                q.offer(temp.left);
            if (temp.right != null)
                q.offer(temp.right);
        }
        if (key_node != null) {
            int x = temp.data;
            key_node.data = x;
            deletDeepest(root, temp);
        }
        return root;
    }

    // Inorder tree traversal (Left - Root - Right)
    public static void inorderTraversal(Node root) {
        if (root == null)
            return;
        inorderTraversal(root.left);
        System.out.print(root.data + " ");
        inorderTraversal(root.right);
    }

    // Preorder tree traversal (Root - Left - Right)
    public static void preorderTraversal(Node root) {
        if (root == null)
            return;
        System.out.print(root.data + " ");
        preorderTraversal(root.left);
        preorderTraversal(root.right);
    }

    // Postorder tree traversal (Left - Right - Root)
    public static void postorderTraversal(Node root) {
        if (root == null)
            return;
        postorderTraversal(root.left);
        postorderTraversal(root.right);
        System.out.print(root.data + " ");
    }

    // Function for Level order tree traversal
    public static void levelorderTraversal(Node root) {
        if (root == null)
            return;

        // Queue for level order traversal
        Queue<Node> q = new LinkedList<>();
        q.offer(root);
        while (!q.isEmpty()) {
            Node temp = q.poll();
            System.out.print(temp.data + " ");
            // Push left child in the queue
            if (temp.left != null)
                q.offer(temp.left);
            // Push right child in the queue
            if (temp.right != null)
                q.offer(temp.right);
        }
    }

    /* Driver function to check the above algorithm. */
    public static void main(String[] args) {
        Node root = null;
        // Insertion of nodes
        root = insert(root, 10);
        root = insert(root, 20);
        root = insert(root, 30);
        root = insert(root, 40);

        System.out.print("Preorder traversal: ");
        preorderTraversal(root);

        System.out.print("\nInorder traversal: ");
        inorderTraversal(root);

        System.out.print("\nPostorder traversal: ");
        postorderTraversal(root);

        System.out.print("\nLevel order traversal: ");
        levelorderTraversal(root);

        // Delete the node with data = 20
        root = deletion(root, 20);

        System.out.print("\nInorder traversal after deletion: ");
        inorderTraversal(root);
    }
}
Python
from collections import deque

# Node class to define the structure of the node
class Node:
    def __init__(self, val):
        self.data = val
        self.left = self.right = None

# Function to insert nodes
def insert(root, data):
    # If tree is empty, new node becomes the root
    if root is None:
        root = Node(data)
        return root
    
    # Queue to traverse the tree and find the position to insert the node
    q = deque()
    q.append(root)
    while q:
        temp = q.popleft()
        # Insert node as the left child of the parent node
        if temp.left is None:
            temp.left = Node(data)
            break
        # If the left child is not null push it to the queue
        else:
            q.append(temp.left)
        # Insert node as the right child of parent node
        if temp.right is None:
            temp.right = Node(data)
            break
        # If the right child is not null push it to the queue
        else:
            q.append(temp.right)
    return root

# Function to delete the given deepest node (d_node) in binary tree
def deletDeepest(root, d_node):
    q = deque()
    q.append(root)
    # Do level order traversal until last node
    while q:
        temp = q.popleft()
        if temp == d_node:
            temp = None
            del d_node
            return
        if temp.right:
            if temp.right == d_node:
                temp.right = None
                del d_node
                return
            else:
                q.append(temp.right)
        if temp.left:
            if temp.left == d_node:
                temp.left = None
                del d_node
                return
            else:
                q.append(temp.left)

# Function to delete element in binary tree
def deletion(root, key):
    if not root:
        return None
    if root.left is None and root.right is None:
        if root.data == key:
            return None
        else:
            return root
    
    q = deque()
    q.append(root)
    temp = None
    key_node = None
    # Do level order traversal to find deepest node (temp) and node to be deleted (key_node)
    while q:
        temp = q.popleft()
        if temp.data == key:
            key_node = temp
        if temp.left:
            q.append(temp.left)
        if temp.right:
            q.append(temp.right)
    
    if key_node is not None:
        x = temp.data
        key_node.data = x
        deletDeepest(root, temp)
    return root

# Inorder tree traversal (Left - Root - Right)
def inorderTraversal(root):
    if not root:
        return
    inorderTraversal(root.left)
    print(root.data, end=" ")
    inorderTraversal(root.right)

# Preorder tree traversal (Root - Left - Right)
def preorderTraversal(root):
    if not root:
        return
    print(root.data, end=" ")
    preorderTraversal(root.left)
    preorderTraversal(root.right)

# Postorder tree traversal (Left - Right - Root)
def postorderTraversal(root):
    if root is None:
        return
    postorderTraversal(root.left)
    postorderTraversal(root.right)
    print(root.data, end=" ")

# Function for Level order tree traversal
def levelorderTraversal(root):
    if root is None:
        return
    
    # Queue for level order traversal
    q = deque()
    q.append(root)
    while q:
        temp = q.popleft()
        print(temp.data, end=" ")
        # Push left child in the queue
        if temp.left:
            q.append(temp.left)
        # Push right child in the queue
        if temp.right:
            q.append(temp.right)

# Driver function to check the above algorithm
if __name__ == "__main__":
    root = None
    # Insertion of nodes
    root = insert(root, 10)
    root = insert(root, 20)
    root = insert(root, 30)
    root = insert(root, 40)

    print("Preorder traversal:", end=" ")
    preorderTraversal(root)

    print("\nInorder traversal:", end=" ")
    inorderTraversal(root)

    print("\nPostorder traversal:", end=" ")
    postorderTraversal(root)

    print("\nLevel order traversal:", end=" ")
    levelorderTraversal(root)

    # Delete the node with data = 20
    root = deletion(root, 20)

    print("\nInorder traversal after deletion:", end=" ")
    inorderTraversal(root)
C#
using System;
using System.Collections.Generic;

// Node class to define the structure of the node
public class Node
{
    public int data;
    public Node left, right;

    // Parameterized Constructor
    public Node(int val)
    {
        data = val;
        left = right = null;
    }
}

public class Program
{
    // Function to insert nodes
    public static Node Insert(Node root, int data)
    {
        // If tree is empty, new node becomes the root
        if (root == null)
        {
            root = new Node(data);
            return root;
        }

        // Queue to traverse the tree and find the position to insert the node
        Queue<Node> q = new Queue<Node>();
        q.Enqueue(root);
        while (q.Count != 0)
        {
            Node temp = q.Dequeue();
            // Insert node as the left child of the parent node
            if (temp.left == null)
            {
                temp.left = new Node(data);
                break;
            }
            // If the left child is not null, push it to the queue
            else
                q.Enqueue(temp.left);

            // Insert node as the right child of parent node
            if (temp.right == null)
            {
                temp.right = new Node(data);
                break;
            }
            // If the right child is not null, push it to the queue
            else
                q.Enqueue(temp.right);
        }
        return root;
    }

    /* function to delete the given deepest node (d_node) in binary tree */
    public static void DeleteDeepest(Node root, Node d_node)
    {
        Queue<Node> q = new Queue<Node>();
        q.Enqueue(root);
        // Do level order traversal until last node
        Node temp;
        while (q.Count != 0)
        {
            temp = q.Dequeue();
            if (temp == d_node)
            {
                temp = null;
                d_node = null;
                return;
            }
            if (temp.right != null)
            {
                if (temp.right == d_node)
                {
                    temp.right = null;
                    d_node = null;
                    return;
                }
                else
                    q.Enqueue(temp.right);
            }
            if (temp.left != null)
            {
                if (temp.left == d_node)
                {
                    temp.left = null;
                    d_node = null;
                    return;
                }
                else
                    q.Enqueue(temp.left);
            }
        }
    }

    /* function to delete element in binary tree */
    public static Node Deletion(Node root, int key)
    {
        if (root == null)
            return null;
        if (root.left == null && root.right == null)
        {
            if (root.data == key)
                return null;
            else
                return root;
        }

        Queue<Node> q = new Queue<Node>();
        q.Enqueue(root);
        Node temp = new Node(0);
        Node key_node = null;
        // Do level order traversal to find deepest node (temp) and node to be deleted (key_node)
        while (q.Count != 0)
        {
            temp = q.Dequeue();
            if (temp.data == key)
                key_node = temp;
            if (temp.left != null)
                q.Enqueue(temp.left);
            if (temp.right != null)
                q.Enqueue(temp.right);
        }

        if (key_node != null)
        {
            int x = temp.data;
            key_node.data = x;
            DeleteDeepest(root, temp);
        }
        return root;
    }

    // Inorder tree traversal (Left - Root - Right)
    public static void InorderTraversal(Node root)
    {
        if (root == null)
            return;
        InorderTraversal(root.left);
        Console.Write(root.data + " ");
        InorderTraversal(root.right);
    }

    // Preorder tree traversal (Root - Left - Right)
    public static void PreorderTraversal(Node root)
    {
        if (root == null)
            return;
        Console.Write(root.data + " ");
        PreorderTraversal(root.left);
        PreorderTraversal(root.right);
    }

    // Postorder tree traversal (Left - Right - Root)
    public static void PostorderTraversal(Node root)
    {
        if (root == null)
            return;
        PostorderTraversal(root.left);
        PostorderTraversal(root.right);
        Console.Write(root.data + " ");
    }

    // Function for Level order tree traversal
    public static void LevelorderTraversal(Node root)
    {
        if (root == null)
            return;

        // Queue for level order traversal
        Queue<Node> q = new Queue<Node>();
        q.Enqueue(root);
        while (q.Count != 0)
        {
            Node temp = q.Dequeue();
            Console.Write(temp.data + " ");
            // Push left child in the queue
            if (temp.left != null)
                q.Enqueue(temp.left);
            // Push right child in the queue
            if (temp.right != null)
                q.Enqueue(temp.right);
        }
    }

    /* Driver function to check the above algorithm. */
    public static void Main(string[] args)
    {
        Node root = null;
        // Insertion of nodes
        root = Insert(root, 10);
        root = Insert(root, 20);
        root = Insert(root, 30);
        root = Insert(root, 40);

        Console.Write("Preorder traversal: ");
        PreorderTraversal(root);

        Console.Write("\nInorder traversal: ");
        InorderTraversal(root);

        Console.Write("\nPostorder traversal: ");
        PostorderTraversal(root);

        Console.Write("\nLevel order traversal: ");
        LevelorderTraversal(root);

        // Delete the node with data = 20
        root = Deletion(root, 20);

        Console.Write("\nInorder traversal after deletion: ");
        InorderTraversal(root);
    }
}
Javascript
// Node class to define the structure of the node
class Node {
    constructor(val) {
        this.data = val;
        this.left = null;
        this.right = null;
    }
}

// Function to insert nodes
function insert(root, data) {
    // If tree is empty, new node becomes the root
    if (root === null) {
        root = new Node(data);
        return root;
    }
    // queue to traverse the tree and find the position to
    // insert the node
    const q = [];
    q.push(root);
    while (q.length !== 0) {
        const temp = q.shift();
        // Insert node as the left child of the parent node
        if (temp.left === null) {
            temp.left = new Node(data);
            break;
        }
        // If the left child is not null push it to the
        // queue
        else
            q.push(temp.left);
        // Insert node as the right child of parent node
        if (temp.right === null) {
            temp.right = new Node(data);
            break;
        }
        // If the right child is not null push it to the
        // queue
        else
            q.push(temp.right);
    }
    return root;
}

/* function to delete the given deepest node
(d_node) in binary tree */
function deletDeepest(root, d_node) {
    const q = [];
    q.push(root);
    // Do level order traversal until last node
    let temp;
    while (q.length !== 0) {
        temp = q.shift();
        if (temp === d_node) {
            temp = null;
            delete d_node;
            return;
        }
        if (temp.right) {
            if (temp.right === d_node) {
                temp.right = null;
                delete d_node;
                return;
            }
            else
                q.push(temp.right);
        }
        if (temp.left) {
            if (temp.left === d_node) {
                temp.left = null;
                delete d_node;
                return;
            }
            else
                q.push(temp.left);
        }
    }
}

/* function to delete element in binary tree */
function deletion(root, key) {
    if (!root)
        return null;
    if (root.left === null && root.right === null) {
        if (root.data === key)
            return null;
        else
            return root;
    }
    const q = [];
    q.push(root);
    let temp;
    let key_node = null;
    // Do level order traversal to find deepest
    // node(temp) and node to be deleted (key_node)
    while (q.length !== 0) {
        temp = q.shift();
        if (temp.data === key)
            key_node = temp;
        if (temp.left)
            q.push(temp.left);
        if (temp.right)
            q.push(temp.right);
    }
    if (key_node !== null) {
        const x = temp.data;
        key_node.data = x;
        deletDeepest(root, temp);
    }
    return root;
}

// Inorder tree traversal (Left - Root - Right)
function inorderTraversal(root) {
    if (!root)
        return;
    inorderTraversal(root.left);
    console.log(root.data + " ");
    inorderTraversal(root.right);
}

// Preorder tree traversal (Root - Left - Right)
function preorderTraversal(root) {
    if (!root)
        return;
    console.log(root.data + " ");
    preorderTraversal(root.left);
    preorderTraversal(root.right);
}

// Postorder tree traversal (Left - Right - Root)
function postorderTraversal(root) {
    if (root === null)
        return;
    postorderTraversal(root.left);
    postorderTraversal(root.right);
    console.log(root.data + " ");
}

// Function for Level order tree traversal
function levelorderTraversal(root) {
    if (root === null)
        return;

    // Queue for level order traversal
    const q = [];
    q.push(root);
    while (q.length !== 0) {
        const temp = q.shift();
        console.log(temp.data + " ");
        // Push left child in the queue
        if (temp.left)
            q.push(temp.left);
        // Push right child in the queue
        if (temp.right)
            q.push(temp.right);
    }
}

/* Driver function to check the above algorithm. */
let root = null;
// Insertion of nodes
root = insert(root, 10);
root = insert(root, 20);
root = insert(root, 30);
root = insert(root, 40);

console.log("Preorder traversal: ");
preorderTraversal(root);

console.log("\nInorder traversal: ");
inorderTraversal(root);

console.log("\nPostorder traversal: ");
postorderTraversal(root);

console.log("\nLevel order traversal: ");
levelorderTraversal(root);

// Delete the node with data = 20
root = deletion(root, 20);

console.log("\nInorder traversal after deletion: ");
inorderTraversal(root);
C++14
#include <bits/stdc++.h>
using namespace std;

// Node class to define the structure of the node
class Node {
public:
    int data;
    Node *left, *right;
    // Parameterized Constructor
    Node(int val)
    {
        data = val;
        left = right = NULL;
    }
};

// Function to insert nodes
Node* insert(Node* root, int data)
{
    // If tree is empty, new node becomes the root
    if (root == NULL) {
        root = new Node(data);
        return root;
    }
    // queue to traverse the tree and find the position to
    // insert the node
    queue<Node*> q;
    q.push(root);
    while (!q.empty()) {
        Node* temp = q.front();
        q.pop();
        // Insert node as the left child of the parent node
        if (temp->left == NULL) {
            temp->left = new Node(data);
            break;
        }
        // If the left child is not null push it to the
        // queue
        else
            q.push(temp->left);
        // Insert node as the right child of parent node
        if (temp->right == NULL) {
            temp->right = new Node(data);
            break;
        }
        // If the right child is not null push it to the
        // queue
        else
            q.push(temp->right);
    }
    return root;
}

/* function to delete the given deepest node
(d_node) in binary tree */
void deletDeepest(Node* root, Node* d_node)
{
    queue<Node*> q;
    q.push(root);
    // Do level order traversal until last node
    Node* temp;
    while (!q.empty()) {
        temp = q.front();
        q.pop();
        if (temp == d_node) {
            temp = NULL;
            delete (d_node);
            return;
        }
        if (temp->right) {
            if (temp->right == d_node) {
                temp->right = NULL;
                delete (d_node);
                return;
            }
            else
                q.push(temp->right);
        }
        if (temp->left) {
            if (temp->left == d_node) {
                temp->left = NULL;
                delete (d_node);
                return;
            }
            else
                q.push(temp->left);
        }
    }
}

/* function to delete element in binary tree */
Node* deletion(Node* root, int key)
{
    if (!root)
        return NULL;
    if (root->left == NULL && root->right == NULL) {
        if (root->data == key)
            return NULL;
        else
            return root;
    }
    queue<Node*> q;
    q.push(root);
    Node* temp;
    Node* key_node = NULL;
    // Do level order traversal to find deepest
    // node(temp) and node to be deleted (key_node)
    while (!q.empty()) {
        temp = q.front();
        q.pop();
        if (temp->data == key)
            key_node = temp;
        if (temp->left)
            q.push(temp->left);
        if (temp->right)
            q.push(temp->right);
    }
    if (key_node != NULL) {
        int x = temp->data;
        key_node->data = x;
        deletDeepest(root, temp);
    }
    return root;
}

// Inorder tree traversal (Left - Root - Right)
void inorderTraversal(Node* root)
{
    if (!root)
        return;
    inorderTraversal(root->left);
    cout << root->data << " ";
    inorderTraversal(root->right);
}

// Preorder tree traversal (Root - Left - Right)
void preorderTraversal(Node* root)
{
    if (!root)
        return;
    cout << root->data << " ";
    preorderTraversal(root->left);
    preorderTraversal(root->right);
}

// Postorder tree traversal (Left - Right - Root)
void postorderTraversal(Node* root)
{
    if (root == NULL)
        return;
    postorderTraversal(root->left);
    postorderTraversal(root->right);
    cout << root->data << " ";
}

// Function for Level order tree traversal
void levelorderTraversal(Node* root)
{
    if (root == NULL)
        return;

    // Queue for level order traversal
    queue<Node*> q;
    q.push(root);
    while (!q.empty()) {
        Node* temp = q.front();
        q.pop();
        cout << temp->data << " ";
        // Push left child in the queue
        if (temp->left)
            q.push(temp->left);
        // Push right child in the queue
        if (temp->right)
            q.push(temp->right);
    }
}

/* Driver function to check the above algorithm. */
int main()
{
    Node* root = NULL;
    // Insertion of nodes
    root = insert(root, 10);
    root = insert(root, 20);
    root = insert(root, 30);
    root = insert(root, 40);

    cout << "Preorder traversal: ";
    preorderTraversal(root);

    cout << "\nInorder traversal: ";
    inorderTraversal(root);

    cout << "\nPostorder traversal: ";
    postorderTraversal(root);

    cout << "\nLevel order traversal: ";
    levelorderTraversal(root);

    // Delete the node with data = 20
    root = deletion(root, 20);

    cout << "\nInorder traversal after deletion: ";
    inorderTraversal(root);
}

Output
Preorder traversal: 10 20 40 30 
Inorder traversal: 40 20 10 30 
Postorder traversal: 40 20 30 10 
Level order traversal: 10 20 30 40 
Inorder traversal after deletion: 40 10 30 

Introduction to Binary Tree – Data Structure and Algorithm Tutorials

Binary Tree is a non-linear data structure where each node has at most two children. In this article, we will cover all the basics of Binary Tree, Operations on Binary Tree, its implementation, advantages, disadvantages which will help you solve all the problems based on Binary Tree.

Table of Content

  • What is Binary Tree?
  • Representation of Binary Tree
  • Types of Binary Tree
  • Operations On Binary Tree
    • Insertion in Binary Tree
    • Traversal of Binary Tree
    • Deletion in Binary Tree
    • Searching in Binary Tree
  • Auxiliary Operations On Binary Tree
  • Implementation of Binary Tree
  • Complexity Analysis of Binary Tree Operations
  • Advantages of Binary Tree
  • Disadvantages of Binary Tree
  • Applications of Binary Tree
  • Frequently Asked Questions on Binary Tree

Similar Reads

What is Binary Tree?

Binary tree is a tree data structure(non-linear) in which each node can have at most two children which are referred to as the left child and the right child....

Representation of Binary Tree

Each node in a Binary Tree has three parts:...

Types of Binary Tree

Binary Tree can be classified into multiples types based on multiple factors:...

Operations On Binary Tree

1. Insertion in Binary Tree...

1. Insertion in Binary Tree

We can insert a node anywhere in a binary tree by inserting the node as the left or right child of any node or by making the node as root of the tree....

2. Traversal of Binary Tree

Traversal of Binary Tree involves visiting all the nodes of the binary tree. Tree Traversal algorithms can be classified broadly into two categories:...

3. Deletion in Binary Tree

We can delete any node in the binary tree and rearrange the nodes after deletion to again form a valid binary tree....

4. Searching in Binary Tree

We can search for an element in the node by using any of the traversal techniques....

Auxiliary Operations On Binary Tree

Finding the height of the treeFind level of a node in a Binary treeFinding the size of the entire tree...

Implementation of Binary Tree

Below is the code for insertion, deletion and traversal of the binary tree:...

Complexity Analysis of Binary Tree Operations

Operations Time Complexity Space Complexity Insertion O(N)O(N) Preorder TraversalO(N)O(N) Inorder Traversal O(N) O(N) Postorder TraversalO(N) O(N) Level Order TraversalO(N) O(N) Deletion O(N) O(N) Searching O(N) O(N)...

Advantages of Binary Tree

Efficient Search: Binary trees are efficient when searching for a specific element, as each node has at most two child nodes, allowing for binary search algorithms to be used.Memory Efficient: Binary trees require lesser memory as compared to other tree data structures, therefore they are memory-efficient.Binary trees are relatively easy to implement and understand as each node has at most two children, left child and right child....

Disadvantages of Binary Tree

Limited structure: Binary trees are limited to two child nodes per node, which can limit their usefulness in certain applications. For example, if a tree requires more than two child nodes per node, a different tree structure may be more suitable.Unbalanced trees: Unbalanced binary trees, where one subtree is significantly larger than the other, can lead to inefficient search operations. This can occur if the tree is not properly balanced or if data is inserted in a non-random order.Space inefficiency: Binary trees can be space inefficient when compared to other data structures. This is because each node requires two child pointers, which can be a significant amount of memory overhead for large trees.Slow performance in worst-case scenarios: In the worst-case scenario, a binary tree can become degenerate or skewed, meaning that each node has only one child. In this case, search operations can degrade to O(n) time complexity, where n is the number of nodes in the tree....

Applications of Binary Tree

Binary Tree can be used to represent hierarchical data.Huffman Coding trees are used in data compression algorithms.Priority Queue is another application of binary tree that is used for searching maximum or minimum in O(1) time complexity.Useful for indexing segmented at the database is useful in storing cache in the system,Binary trees can be used to implement decision trees, a type of machine learning algorithm used for classification and regression analysis....

Frequently Asked Questions on Binary Tree

1. What is a binary tree?...

Conclusion:

Tree is a hierarchical data structure. Main uses of trees include maintaining hierarchical data, providing moderate access and insert/delete operations. Binary trees are special cases of tree where every node has at most two children....