建立中序线索二叉树

#include<stdio.h>
#include<stdlib.h>
typedef int DataType;

typedef struct BiThrNode{
    DataType data;
    struct BiThrNode *lchild;
    struct BiThrNode *rchild;
    unsigned ltag;
    unsigned rtag;
}BiThrNode,*BiThrTree;

BiThrTree pre;

void InThreading(BiThrTree p){
    if(p){
    InThreading(p->lchild);
    if(!(p->lchild)){
    p->ltag=1;
    p->lchild=pre;
    }
    if(!pre->rchild){
    pre->rtag=1;
    pre->rchild=p;
   }
   pre=p;
   InThreading(p->rchild);
  }
}
int InOrderThr(BiThrTree *head,BiThrTree T){
    (*head)=new BiThrNode;
    if(!(head))
        return 0;
    (*head)->ltag=0;
    (*head)->rtag=1;
    (*head)->rchild=(*head);
    if(!T)
    (*head)->lchild=*head;
    else{
    (*head)->lchild=T;
    pre=*head;
    InThreading(T);
    pre->rchild=*head;
    pre->rtag=1;
    (*head)->rchild=pre;
    }
    return 1;
}

int main( )
{
    BiThrTree T;
    BiThrTree *head;
    return 0;
}