text: 
  
  /* you only have to complete the function given below.  
  Node is defined as  
  
  class Node {
      public:
          int data;
          Node *left;
          Node *right;
          Node(int d) {
              data = d;
              left = NULL;
              right = NULL;
          }
  };
  
  */
  
      void preOrder(Node *root) {
          if(root == NULL) return;
          std::cout<< root->data << " ";
          preOrder(root->left);
          preOrder(root->right);
      }
  
  