Data Structure Binary Tree: Convert an arbitrary Binary Tree to a tree that holds Children Sum Property

http://www.geeksforgeeks.org/convert-an-arbitrary-binary-tree-to-a-tree-that-holds-children-sum-property/

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

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

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

 void _convert(node* root, int diff) {
     if (!root) return;
     if (root->left) {
         root->left->data += diff;
         _convert(root->left, diff);
     }
     else if (root->right) {
         root->right->data += diff;
         _convert(root->right, diff);
     }
 }

 void convert(node* root) {
     if (!root || !root->left && !root->right) return;
     convert(root->left);
     convert(root->right);
     int sum = ;
     sum += root->left? root->left->data : ;
     sum += root->right? root->right->data : ;
     if (sum >= root->data) root->data = sum;
     else _convert(root, root->data - sum);
 }

 int main() {
     struct node* root = new node();
     root->left = new node();
     root->right = new node();
     root->left->left = new node();
     root->left->right = new node();
     root->right->left = new node();
     root->right->right = new node();
     print(root);
     cout << endl;
     convert(root);
     print(root);
     return ;
 }