Tree Traversal for C++

t_traverse.cpp

// C program for different tree traversals
#include <iostream>
using namespace std;

/* A binary tree node has data, pointer to left child
and a pointer to right child */
struct Node
{
	int data;
	struct Node* left, *right;
	Node(int data)
	{
		this->data = data;
		left = right = NULL;
	}
};

/* 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 << " ";
}

/* Given a binary tree, print its nodes in inorder*/
void printInorder(struct Node* node)
{
	if (node == NULL)
		return;

	/* first recur on left child */
	printInorder(node->left);

	/* then print the data of node */
	cout << node->data << " ";

	/* now recur on right child */
	printInorder(node->right);
}

/* Given a binary tree, print its nodes in preorder*/
void printPreorder(struct Node* node)
{
	if (node == NULL)
		return;

	/* first print data of node */
	cout << node->data << " ";

	/* then recur on left sutree */
	printPreorder(node->left);

	/* now recur on right subtree */
	printPreorder(node->right);
}

/* Driver program to test above functions*/
int main()
{
	struct Node *root = new Node(1);
	root->left			 = new Node(2);
	root->right		 = new Node(3);
	root->left->left	 = new Node(4);
	root->left->right = new Node(5);

	cout << "\nPreorder traversal of binary tree is \n";
	printPreorder(root);

	cout << "\nInorder traversal of binary tree is \n";
	printInorder(root);

	cout << "\nPostorder traversal of binary tree is \n";
	printPostorder(root);
  cout << endl;
	return 0;
}