bintree

#include <iostream>
#include <stdlib.h>

using namespace std;

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


struct node *newNode(int data)
{
        struct node *node = (struct node *) malloc(sizeof(struct node));
        node ->data = data;
        node->left = NULL;
        node->right= NULL;
        return (node);
}

void preorder(struct node *temp)
{
        if(temp)
        {
           cout << " " << temp->data;
           preorder(temp->left);
           preorder(temp->right);
        }

}

void inorder(struct node *temp)
{
        if(temp)
        {
          inorder(temp->left);
          cout << " " << temp->data;
          inorder(temp->right);

        }

}

void postorder(struct node *temp)
{
        if(temp)
        {
           postorder(temp->left);
           postorder(temp->right);
           cout << " " << temp->data;

        }
}

int main()
{
        struct node* root = newNode(1);
        root->left = newNode(2);
        root->right = newNode(3);
        root->left->left = newNode(4);
        root->right->left = newNode(9);
        cout << "preorder: ";
        preorder(root);
        cout << "\ninorder: ";
        inorder(root);
        cout << "\npostorder: ";
        postorder(root);
}