1 #include<stdio.h>
2
3 typedef struct Tree{
4 char data;
5 struct Tree* left;
6 struct Tree* right;
7 }Tree;
8
9 void pre_travel(Tree* ptree){
10 if(ptree){
11 printf("%c",ptree->data);
12 if(ptree->left)
13 pre_travel(ptree->left);
14 if(ptree->right)
15 pre_travel(ptree->right);
16 }
17 }
18
19 void in_travel(Tree* ptree){
20 if(ptree){
21 if(ptree->left)
22 pre_travel(ptree->left);
23 printf("%c",ptree->data);
24 if(ptree->right)
25 pre_travel(ptree->right);
26 }
27
28 }
29
30 void post_travel(Tree* ptree){
31 if(ptree){
32 if(ptree->left)
33 pre_travel(ptree->left);
34 if(ptree->right)
35 pre_travel(ptree->right);
36 printf("%c",ptree->data);
37 }
38
39 };
40
41 int main(){
42 Tree tree[5];
43 int i=0;
44 for(i=0;i<5;i++){
45 tree[i].data='A'+i;
46 }
47 tree[0].left=&tree[1];
48 tree[0].right=&tree[2];
49 tree[1].left=&tree[3];
50 tree[1].right=&tree[4];
51 for(i=2;i<5;i++){
52 tree[i].left=NULL;
53 tree[i].right=NULL;
54 }
55 printf("pre_order\n");
56 pre_travel(&tree[0]);
57 printf("in_order\n");
58 in_travel(&tree[0]);
59 printf("post_order\n");
60 post_travel(&tree[0]);
61 return 0;
62 }
