1 #include "stdio.h"
 2 #include "stdlib.h" 
 3 
 4 typedef struct BTree 
 5 {
 6     int data;
 7     struct BTree * lchild;
 8     struct BTree * rchild;
 9 }BTreeNode, *PBTree;
10 
11 
12 
13 void Create_Tree ( PBTree T )
14 {
15     int num;
16     scanf ( "%d", &num );
17     if ( num == 0 )
18         T = NULL;
19     else
20     {
21         T = ( PBTree ) malloc ( sizeof (BTreeNode) );
22 
23         T->data = num;
24     
25         Create_Tree ( T->lchild );
26         Create_Tree ( T->rchild );
27     }
28 }
29 
30 
31 void Show_Tree ( PBTree T )
32 {
33     if (T)
34     {
35         printf ( "%d\t", T->data );
36         Show_Tree ( T->lchild );
37         Show_Tree ( T->rchild );
38     }
39 }
40 
41 
42 
43 int main ( void )
44 {
45     PBTree T = NULL;
46     Create_Tree ( T );
47 
48     Show_Tree ( T );
49 
50     return 0;