class TreeNode:

    def __init__(self, data):

        self.data = data

        self.left = None

        self.right = None

​

def inOrderTraversal(node):

    if node is None:

        return

    inOrderTraversal(node.left)

    print(node.data, end=", ")

    inOrderTraversal(node.right)

​

root = TreeNode(13)

node7 = TreeNode(7)

node15 = TreeNode(15)

node3 = TreeNode(3)

node8 = TreeNode(8)

node14 = TreeNode(14)

node19 = TreeNode(19)

node18 = TreeNode(18)

​

root.left = node7

root.right = node15

​

node7.left = node3

node7.right = node8

​

node15.left = node14

node15.right = node19

​

node19.left = node18

​

# Traverse

inOrderTraversal(root)

​

#Python

#include <stdio.h>

#include <stdlib.h>

​

typedef struct TreeNode {

    int data;

    struct TreeNode* left;

    struct TreeNode* right;

} TreeNode;

​

TreeNode* newTreeNode(int data) {

    TreeNode* node = (TreeNode*)malloc(sizeof(TreeNode));

    node->data = data;

    node->left = NULL;

    node->right = NULL;

    return node;

}

​

void inOrderTraversal(TreeNode* node) {

    if (node == NULL)

        return;

    inOrderTraversal(node->left);

    printf("%d, ", node->data);

    inOrderTraversal(node->right);

}

​

int main() {

    TreeNode* root = newTreeNode(13);

    root->left = newTreeNode(7);

    root->right = newTreeNode(15);

​

    root->left->left = newTreeNode(3);

    root->left->right = newTreeNode(8);

​

    root->right->left = newTreeNode(14);

    root->right->right = newTreeNode(19);

​

    root->right->right->left = newTreeNode(18);

​

    inOrderTraversal(root);

    return 0;

}

​

//C

public class Main {

​

    public static class TreeNode {

        int data;

        TreeNode left;

        TreeNode right;

​

        TreeNode(int data) {

            this.data = data;

            left = null;

            right = null;

        }

    }

​

    public static void inOrderTraversal(TreeNode node) {

        if (node == null)

            return;

        inOrderTraversal(node.left);

        System.out.print(node.data + ", ");

        inOrderTraversal(node.right);

    }

​

    public static void main(String[] args) {

        TreeNode root = new TreeNode(13);

        root.left = new TreeNode(7);

        root.right = new TreeNode(15);

​

        root.left.left = new TreeNode(3);

        root.left.right = new TreeNode(8);

​

        root.right.left = new TreeNode(14);

        root.right.right = new TreeNode(19);

​

        root.right.right.left = new TreeNode(18);

​

        inOrderTraversal(root);

    }

}

​

// Java

​