1 typedef int Data;
 2
 3 struct TreeNode{
 4     Data data;
 5     TreeNode *left;
 6     TreeNode *right;
 7 };
 8
 9 /*
10 建立一棵num个元素的有序二叉树
11 */
12 TreeNode *create_tree(int num){
13     TreeNode *root,*p,*child,*parent;
14     int i=0;
15     p=(TreeNode *)malloc(sizeof(TreeNode));
16     p->left=p->right=NULL;
17     cin>>p->data;
18     child=root=p;
19     while (++i<num){
20         p=(TreeNode *)malloc(sizeof(TreeNode));
21         p->left=p->right=NULL;
22         cin>>p->data;
23         while (child){
24             parent=child;
25             if ((p->data)>(child->data)){
26                 child=child->right;
27             }else{
28                 child=child->left;
29             }
30         }
31         if (p->data>parent->data){
32             parent->right=p;
33         }else{
34             parent->left=p;
35         }
36         child=root;
37     }
38     return root;
39 }

 1 //非递归中序输出
 2 void midOrder(TreeNode *t){
 3     Stack s={0};
 4     TreeNode *p=NULL;
 5     push(&s,t);
 6     while(!empty_stack(&s)){
 7         if (t->left){
 8             push(&s,t->left);
 9             t=t->left;
10         }else{
11             t=pop(&s);
12             cout<<t->data<<ends;
13             while (!(t->right)&&!empty_stack(&s)){
14                 t=pop(&s);
15                 cout<<t->data<<ends;
16             }
17             if (t->right){
18                 push(&s,t->right);
19                 t=t->right;
20             }
21         }
22     }
23 }
24
25 //非递归前序输出
26 void preOrder(TreeNode *t){
27     Stack s={0};
28     TreeNode *p=NULL;
29     push(&s,t);
30     while (!empty_stack(&s)){
31         t=pop(&s);
32         cout<<t->data<<ends;
33         if (t->right){
34             push(&s,t->right);
35         }
36         if (t->left){
37             push(&s,t->left);
38         }
39     }
40 }
41
42 //非递归后序输出
43 void postOrder(TreeNode *t){
44     Stack s={0};
45     TreeNode *p=NULL;
46     push(&s,t);
47     while (!empty_stack(&s)){
48         if (t->left||t->right){        //如果t有孩子，则将孩子入栈
49             if (t->left){
50                 if (t->right){
51                     push(&s,t->right);
52                 }
53                 push(&s,t->left);
54                 t=t->left;
55             }else{
56                 push(&s,t->right);
57                 t=t->right;
58             }
59         }else{
60             t=pop(&s);            //从栈中取出叶子节点t
61             cout<<t->data<<ends;
62             while (!empty_stack(&s)){
63                 p=pop(&s);                    //取出上一个压入栈的节点
64                 if (p->left==t||p->right==t){//判断该节点是不是t的父节点,如果是则输出数据
65                     cout<<p->data<<ends;
66                     t=p;
67                 }else{
68                     t=p;
69                     push(&s,p);
70                     break;
71                 }
72             }
73         }
74     }
75 }