Node* Copy(Node* node) { if (!node) return NULL; Node* newNode = new Node(); CopyImpl(newNode, node); return newNode; } void CopyImpl(Node* target, Node* src) { target->value = src->value; if (src->left) { target->left = new Node(); CopyImpl(target->left, src->left); } else { target->left = NULL; } if (src->right) { target->right = new Node(); CopyImpl(target->right, src->right); } else { target->right = NULL; } }