Data Structure Binary Tree: Boundary Traversal of binary tree

http://www.geeksforgeeks.org/boundary-traversal-of-binary-tree/

#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <stack>
#include <string>
#include <fstream>
#include <map>
using namespace std;

struct node {
    int data;
    struct node *left, *right;
    node() : data(0), left(NULL), right(NULL) { }
    node(int d) : data(d), left(NULL), right(NULL) { }
};

void printleft(node *root) {
    if (!root) return;
    if (root->left) {
        cout << root->data << " ";
        printleft(root->left);
    }
    else if (root->right) {
        cout << root->data << " ";
        printleft(root->right);
    }
}

void printleaf(node *root) {
    if (!root) return;
    printleaf(root->left);
    if (!root->left && !root->right) cout << root->data << " ";
    printleaf(root->right);
}

void printright(node *root) {
    if (!root) return;
    if (root->right) {
        printright(root->right);
        cout << root->data << " ";
    }
    else if (root->left) {
        printright(root->left);
        cout << root->data << " ";
    }
}

void printboundary(node *root) {
    if (!root) return;
    cout << root->data << " ";
    printleft(root->left);
    printleaf(root);
    printright(root->right);
}

int main() {
    node *root = new node(20);
    root->left = new node(8);
    root->right = new node(22);
    root->left->left = new node(4);
    root->left->right = new node(12);
    root->right->right = new node(25);
    root->left->right->left = new node(10);
    root->left->right->right = new node(14);
    printboundary(root);
    return 0;
}