C++练习 | 求解二叉树的高度

int h(BTree *bt)
{
    if(bt->lchild==NULL&&bt->rchild==NULL)
        return ;
    if(bt->lchild!=NULL&&bt->rchild==NULL)
        return +h(bt->lchild);
    if(bt->lchild==NULL&&bt->rchild!=NULL)
        return +h(bt->rchild);
    return +max(h(bt->rchild),h(bt->lchild));
}