postorder traversal c++

#include<iostream>
using namespace std;

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

void preorder(struct node *root) {
   if (root != NULL) {
      cout<<root->data<<" ";
      preorder(root->left);
      preorder(root->right);
   }
}

/* Given a binary tree, print its nodes according to the 
"bottom-up" postorder traversal. */
void printPostorder(struct Node* node) 
{ 
    if (node == NULL) 
        return; 
  
    // first recur on left subtree 
    printPostorder(node->left); 
  
    // then recur on right subtree 
    printPostorder(node->right); 
  
    // now deal with the node 
    cout << node->data << " "; 
}