数据结构 二叉树的线索存储

#include <stdio.h>#include <stdlib.h>#include <iostream.h>#define  OK             1#define  ERROR          0#define  OVERFLOW       -2typedef char TElemType;typedef enum {Link,Thread} PointerTag;typedef struct BiThrNode{TElemType data;struct BiThrNode *lchild,*rchild;PointerTag LTag;PointerTag RTag;}BiThrNode, *BiThrTree;BiThrTree pre;void Create_BiThrTree(BiThrTree &T){TElemType ch;cin >> ch;if (ch == '#'){T = NULL;}else{T = (BiThrTree)malloc(sizeof(BiThrNode));if (!T){exit(OVERFLOW);}T->data = ch;Create_BiThrTree(T->lchild);if (T->lchild){T->LTag = Link;}Create_BiThrTree(T->rchild);if (T->rchild){T->RTag = Link;}}}void InThreading(BiThrTree p){if (p){InThreading(p->lchild);if (!p->lchild){p->LTag = Thread;p->lchild = pre;}if (!pre->rchild){pre->RTag = Thread;pre->rchild = p;}pre = p;InThreading(p->rchild);}}int InOrderThreading(BiThrTree &Thrt, BiThrTree T){if (!(Thrt = (BiThrTree)malloc(sizeof(BiThrNode)))){exit(OVERFLOW);}Thrt->LTag = Link;Thrt->RTag = Thread;Thrt->rchild = Thrt;if (!T){Thrt->lchild = Thrt;}else{Thrt->lchild = T;pre = Thrt;InThreading(T);pre->rchild = Thrt;pre->RTag = Thread;Thrt->rchild = pre;}return OK;}int InOrderTraverse_Thr(BiThrTree T){BiThrTree p;p = T->lchild;while (p != T){while (p->LTag == Link){p = p->lchild;}printf("%c",p->data);while (p->RTag == Thread && p->rchild != T){p = p->rchild;printf("%c",p->data);}p = p->rchild ;}return OK;}int main(){BiThrTree T,H;Create_BiThrTree(T);InOrderThreading(H,T);InOrderTraverse_Thr(T);printf("\n");return 0;}