>>577
void ReverseTree(struct BTREE *ptr) {
    struct BTREE *temp;
    if (ptr == NULL) return;
    ReverseTree(ptr->left);
    ReverseTree(ptr->right);
    temp = ptr->left;
    ptr->left = ptr->right;
    ptr->right = temp;
    return;
}
int CountData(struct BTREE *ptr, int searchdata) {
    if (ptr == NULL) return 0;
    return CountData(ptr->left, searchdata) + CountData(ptr->right, searchdata) + (ptr->data == searchdata);
}