中序線索化二叉樹

//樹的線索化中序
#include<iostream>
using namespace std;

typedef struct BiThrNode{
    char data;
    struct BiThrNode *lchild,*rchlild;
    int LTag,RTag;
}BiThrNode,*BiThrTree;

BiThrNode *pre = new BiThrNode;

void CreateBiTree(BiThrNode &T){
    char ch;
    cin>>ch;
    if(ch=='#') T=NULL;
    else{
        T=new BiThrNode;
        T->data=ch;
        CreateBiTree(T->lchild);
        CreateBiTree(T->rchlild);
    }
}

void InThreading(BiThrTree p){
    if(p){
        InThreading(p->lchild);
        if(!p->lchild){
            p->LTag=1;
            p->lchild=pre;
        }else{
            p->LTag;
        }

        if(!pre->rchlild){
            pre->RTag=1;
            pre->rchlild=p;
        }else{
            pre->RTag=0;
        }
        pre=p;
        InThreading(p->rchlild);
    }
}

void main(){
    pre->RTag=1;
    pre->rchlild=NULL;
    BiThrTree tree;
    cout<<"please input:\n";
    CreateBiTree(tree);
    InThreading(tree);
    cout<<"finish!\n";
}