三种递归遍历二叉树

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 
 4 typedef int ElementType;
 5 
 6 struct BinarySearchTreeNode
 7 {
 8     ElementType Element;
 9     struct BinarySearchTreeNode *Left;
10     struct BinarySearchTreeNode *Right;
11 };
12 
13 int BinarySearchTreePreOrder(struct BinarySearchTreeNode *TreeRoot)
14 {
15     if(TreeRoot!=NULL)
16     {
17         printf("%d\n",TreeRoot -> Element);
18         BinarySearchTreePreOrder(TreeRoot->Left);
19         BinarySearchTreePreOrder(TreeRoot->Right);
20     }
21     return 0;
22 }
23 
24 int BinarySearchTreeInOrder(struct BinarySearchTreeNode *TreeRoot)
25 {
26     if(TreeRoot!=NULL)
27     {
28         BinarySearchTreeInOrder(TreeRoot->Left);
29         printf("%d\n",TreeRoot -> Element);
30         BinarySearchTreeInOrder(TreeRoot->Right);
31     }
32     return 0;
33 }
34 
35 int BinarySearchTreePostOrder(struct BinarySearchTreeNode *TreeRoot)
36 {
37     if(TreeRoot!=NULL)
38     {
39         BinarySearchTreePostOrder(TreeRoot->Left);
40         BinarySearchTreePostOrder(TreeRoot->Right);
41         printf("%d\n",TreeRoot -> Element);
42     }
43     return 0;
44 }
45 
46 int main()
47 {
48 //    BinarySearchTreePreOrder(TreeRoot);
49 //    BinarySearchTreeInOrder(TreeRoot);
50     BinarySearchTreePostOrder(TreeRoot);
51     return 0;
52 }