扩展二叉树

 1 #include <iostream>
 2 #include <stdlib.h>
 3 #include <string>
 4 #include <cstring>
 5 #include <algorithm>
 6 #include <cstdio>
 7 using namespace std;
 8 
 9 typedef struct node;
10 typedef node *tree;
11 struct node
12 {
13     char data;
14     tree lchild, rchild;
15 };
16 tree bt;
17 
18 int i;
19 string s;
20 
21 void build(tree &bt)  //建树
22 {
23     if(s[++i]!=‘.‘)
24     {
25         bt = new node; 
26         bt = new node; 
27         bt->data = s[i];
28         build(bt->lchild);  
29         build(bt->rchild);  
30     }
31     else bt = NULL;
32 }
33 void printzx(tree bt)  //输出中序序列 
34 {
35     if(bt)
36     {
37         printzx(bt->lchild);
38         cout << bt->data;
39         printzx(bt->rchild);
40     }
41 }
42 void printhx(tree bt)  //输出后序序列 
43 {
44     if(bt)
45     {
46         printhx(bt->lchild);
47         printhx(bt->rchild);
48         cout << bt->data;
49     }
50 }
51 int main()
52 {
53     cin >> s;
54     i = -1;
55     build(bt);
56     printzx(bt);
57     cout << endl;
58     printhx(bt);
59     cout << endl;
60     return 0;
61 }