有无董哥看看我这个后序线索二叉树哪里建的有问题？

struct tnode
{
int flag;//有左孩的为0，没有左孩的为1；
tnode* parent;
char data;
int ltag;
int rtag;
tnode* right;
tnode* left;
};

void postthread(tnode* t, tnode* post) {

if (t != nullptr) {
    if (t->right == nullptr)//当前节点的后继线索化
    {
        t->right = post;
        t->rtag = 1;
    }
    else
        t->ltag = 0;
    if (post != nullptr && post->ltag == 1)//后继节点的前驱线索化
        post->left = t;
    if (t->left == nullptr)//判断当前节点是否需要前驱线索化
        t->ltag = 1;
    else
        t->ltag = 0;

    post = t;

    if (t->rtag == 0) postthread(t->right, post);
    if (t->ltag == 0)postthread(t->left, post);
    if (t->rtag == 1 && t->ltag == 1)
    {
        while (t->parent->flag == 1)
            t = t->parent;

        postthread(t->parent->left, post);
    }
}

}

void postThreading(TriTree p){
    if(p){
        postThreading(p->lChild);
        postThreading(p->rChild);
        if(!p->lChild){
            p->lTag=1;
            p->lChild=pre;
        }
        if(!pre->rChild){
            pre->rTag=1;
            pre->rChild=p;
        }
        pre=p;
    }
}

bool postThreadTree(TriTree T,TriTree &head){
    if(!(head=new TriTNode)) return false;
    head->lTag=0;
    head->rTag=1;
    head->parent=NULL;
    if(!T){head->lChild=head;head->rChild=head;}
    else{
        pre=head;
        head->lChild=T;
        head->rChild=T;
        T->parent=head;
        postThreading(T);
        if(!pre->rChild){
            pre->rTag=1;
            pre->rChild=head;
        }
    }
    return true;
}