遍历一遍就行了

有编好了的，现成的吗

int LeafNum(TNODE *p) //先序遍历求叶子数.
{
    static int num=0;
    if(p!=NULL)
    {
        if(p->LChild==NULL&&p->Rchild==NULL)
            ++num;
        else
        {
            LeafNum(p->LChild);
            LeafNum(p->Rchild);
        }
    }
    return num;
}