如何建立并遍历二叉树中节点为X的节点,如果找到返回其双亲节点的值否者返回0

如何建立并遍历二叉树中节点为X的节点,如果找到返回其双亲节点的值否者返回0

输入数据是整形的，每输入一个数，回车一次，子树为空输入0.以根左右的方式创建树。输入格式如：
10
21
0
0
51
0
0
该程序已测试，得到正确结果。

#include "stdlib.h"

typedef int Element;

struct Tree
{
Element date;
struct Tree *left, *right;
};

void CreateTree(struct Tree **r);
void PrintTree(struct Tree *r);
int ParentValue(struct Tree *r, int x);
struct Tree *Find2(struct Tree *r , struct Tree **p, int x);

int main()
{
struct Tree *r;

CreateTree(&r);
PrintTree(r);
Element x=1;
printf("\nPlease input the data you want to find:");
scanf("%d",&x);
while (x!=0)
{
int v=ParentValue(r,x);
if (v != 0)
{
printf("\nfind %d",v);
}
else
{
printf("\nnot find!");
}
printf("\nPlease input the data you want to find:");
scanf("%d",&x);
}

return 0;
}

void CreateTree(struct Tree **r)
{
Element ch;
scanf("%d",&ch);
if (ch == 0)
{
*r = NULL;
return ;
}
(*r) = (struct Tree *)malloc(sizeof(struct Tree));
(*r)->date = ch;
CreateTree( ( &(*r)->left));
CreateTree( &((*r)->right));
}
void PrintTree(struct Tree *r)
{
if (r == NULL)
{
return ;
}
printf("%d ",r->date);
PrintTree(r->left);
PrintTree(r->right);
}

int ParentValue(struct Tree *r, Element x)
{
struct Tree *p;
p = NULL;
Find2(r, &p, x);
if (p == NULL)
{
return 0;
}
else
{
return p->date;
}
}

struct Tree *Find2(struct Tree *r , struct Tree **p, int x)
{
if (r == NULL)
{
return NULL;
}
if (r->date == x)
{
return r;
}
struct Tree *temp;
temp = Find2(r->left, p, x);
if (temp != NULL)
{
*p = r;
return NULL;
}
temp = Find2(r->right, p, x);
if (temp != NULL)
{
*p = r;
return NULL;
}
return NULL;
}

额