二叉树的设计实现与遍历
#include<iostream>
2 using namespace std;
3
4 typedef char DataType;//定义DataType为char类型
5
6 //定义节点结构体
7 typedef struct Node
8 {
9 DataType data;
10 struct Node *leftChild;
11 struct Node *rightChild;
12
13 Node(int x): data(x),leftChild(NULL),rightChild(NULL){}//dump()
14
15 }BiTreeNode;
16
17
18 void Destroy(BiTreeNode **root);
19
20
21 //初始化
22 void Initiate(BiTreeNode **root)
23 {
24 *root = (BiTreeNode *)malloc(sizeof(BiTreeNode));
25 (*root)->leftChild = NULL;
26 (*root)->rightChild = NULL;
27 }
28 //左插入节点
29 BiTreeNode *InsertLeftNode(BiTreeNode *curr, DataType x)
30 {
31 BiTreeNode *s, *t;
32 if(curr == NULL)
33 return NULL;
34 t = curr->leftChild;
35 s = (BiTreeNode *)malloc(sizeof(BiTreeNode));
36 s->data = x;
37 s->leftChild = t;
38 s->rightChild = NULL;
39 curr->leftChild = s;
40 return curr->leftChild;
41 }
42 //右插入节点
43 BiTreeNode *InsertRightNode(BiTreeNode *curr, DataType x)
44 {
45 BiTreeNode *s, *t;
46 if(curr == NULL)
47 return NULL;
48 t = curr->rightChild;
49 s = (BiTreeNode *)malloc(sizeof(BiTreeNode));
50 s->data = x;
51 s->rightChild = t;
52 s->leftChild = NULL;
53 curr->rightChild = s;
54 return curr->rightChild;
55 }
57 //左删除子树
58 BiTreeNode *DeleteLeftTree(BiTreeNode *curr)
59 {
60 if(curr == NULL||curr->leftChild == NULL)
61 return NULL;
62 Destroy(&curr->leftChild);
63 curr->leftChild = NULL;
64 return curr;
65 }
66 //右删除子树
67 BiTreeNode *DeleteRightTree(BiTreeNode *curr)
68 {
69 if(curr == NULL || curr->rightChild == NULL)
70 return NULL;
71 Destroy(&curr->rightChild);
72 curr->rightChild = NULL;
73 return curr;
74 }
75 //打印二叉树
76 void PrintBiTree(BiTreeNode *root, int n)
77 {
78 int i;
79 if(root == NULL)
80 return ;
81 PrintBiTree(root->rightChild, n+1);
82 for(i = 0; i< n-1; i++)
83 cout<<" ";
84 if(n>0)
85 {
86 cout<<"--";
87 cout<<root->data<<endl;
88 }
89 PrintBiTree(root->leftChild, n+1);
90 }
//查找数据元素
93 BiTreeNode *Search(BiTreeNode *root, DataType x)
94 {
95 BiTreeNode *find = NULL;
96 if(root != NULL)
97 {
98 if(root->data == x)
99 find =root;
100 else
101 {
102 find = Search(root->leftChild, x);
103 if(find == NULL)
104 find = Search(root->rightChild, x);
105 }
106 }
107 return find;
108 }
//前序遍历非递归
112 void preorder(BiTreeNode *root, void visit(DataType item))
113 {
114 BiTreeNode *cur = root,*prev = NULL;
115 while(cur != NULL)
116 {
117 if(cur->leftChild == NULL)
118 {
119 cout<<cur->data;
120 cur = cur->rightChild;
121 }
122 else
123 {
124 prev = cur->leftChild;
125 while(prev->rightChild != NULL && prev->rightChild != cur)
126 prev = prev->rightChild;
127 if(prev->rightChild == NULL)
128 {
129 cout<<cur->data;
130 prev->rightChild = cur;
131 cur = cur->leftChild;
132 }
133 else
134 {
135 prev->rightChild = NULL;
136 cur = cur->rightChild;
137 }
138 }
139 }
140 }
142 /*//前序遍历递归
143 void preorder(BiTreeNode *root, void visit(DataType item))
144 {
145 if(root != NULL)
146 {
147 visit(root->data);
148 preorder(root->leftChild, visit);
149 preorder(root->rightChild, visit);
150 }
151 }
152 */
//中序遍历非递归
154 void inorder(BiTreeNode *root, void visit(DataType item))
155 {
156 BiTreeNode *cur = root,*prev = NULL;
157 while(cur != NULL)
158 {
159 if(cur->leftChild == NULL)
160 {
161 cout<<cur->data;
162 cur = cur->rightChild;
163 }
164 else
165 {
166 prev = cur->leftChild;
167 while(prev->rightChild != NULL && prev->rightChild != cur)
168 prev = prev->rightChild;
169 if(prev->rightChild == NULL)
170 {
171 prev->rightChild = cur;
172 cur = cur->leftChild;
173 }
174 else
175 {
176 prev->rightChild = NULL;
177 cout<<cur->data;
178 cur = cur->rightChild;
179 }
180 }
181 }
182 }/*
184 //中序遍历递归
185 void inorder(BiTreeNode *root, void visit(DataType item))
186 {
187 if(root !=NULL)
188 {
189 inorder(root->leftChild, viist);
190 visit(root->data);
191 inorder(root->rightChild, visit);
192 }
193 }
194 * */
// 比前两个稍复杂，需要建立临时节点，令其左孩子是root，并且还需要一个子过程，就是倒序输出某两个节点之间路径上的各节点
196 void reverse(BiTreeNode *from, BiTreeNode *to)
197 {
198 if(from == to)
199 return ;
200 BiTreeNode *x =from, *y = from->rightChild, *z;
201 while(true)
202 {
203 z = y->rightChild;
204 y->rightChild = x;
205 x = y;
206 y = z;
207 if(x == to)
208 break;
209 }
210 }
211 void printreverse(BiTreeNode *from, BiTreeNode *to)
212 {
213 reverse(from, to);
214 BiTreeNode *p = to;
215 while(true)
216 {
217 cout<<p->data;
218 if(p == from)
219 break;
220 p = p->rightChild;
221 }
222 reverse(to, from);
223 }
224 void postorder(BiTreeNode *root, void visit(DataType item))
225 {
226 BiTreeNode dump(0);
227 dump.leftChild = root;
228 BiTreeNode *cur = &dump,*prev = NULL;
229 while(cur)
230 {
231 if(cur->leftChild == NULL)
232 {
233 cur = cur->rightChild;
234 }
235 else
236 {
237 prev = cur->leftChild;
238 while(prev->rightChild != NULL && prev->rightChild != cur)
239 prev = prev->rightChild;
240 if(prev->rightChild == NULL)
241 {
242 prev->rightChild = cur;
243 cur = cur->leftChild;
244 }
245 else
246 {
247 printreverse(cur->leftChild, prev);
248 prev->rightChild = NULL;
249 cur = cur->rightChild;
250 }
251 }
252 }
253 }
256 /*
257 //后序遍历递归
258 void inorder(BiTreeNode *root, void visit(DataType item))
259 {
260 if(root != NULL)
261 {
262 postorder(root->leftChild, visit);
263 postorder(root->rightChild, visit);
264 visit(root->data);
265 }
266 }
267 */
//撤销二叉树操作设计
268 void Destroy(BiTreeNode **root)
269 {
270 if((*root) != NULL && (*root)->leftChild != NULL)
271 Destroy(&(*root)->leftChild);
272 if((*root) != NULL && (*root)->rightChild != NULL)
273 Destroy(&(*root)->rightChild);
274 free(*root);
275 }
主函数检测void Visit(DataType item)
278 {
279 cout<<item<<" ";
280 }
281 int main()
282 {
283 BiTreeNode *root, *p, *find;
284 char x = 'E';
285 Initiate(&root);
286 p = InsertLeftNode(root, 'A');
287 p = InsertLeftNode(p, 'B');
288 p = InsertLeftNode(p, 'D');
289 p = InsertRightNode(p, 'G');
290 p = InsertRightNode(root->leftChild, 'C');
291 InsertLeftNode(p, 'E');
292 InsertRightNode(p, 'F');
293 PrintBiTree(root, 0);
294 cout<<"前序遍历："<<endl;
295 preorder(root->leftChild, Visit);
296 cout<<endl;
297 cout<<"中序遍历："<<endl;
298 inorder(root->leftChild, Visit);
299 cout<<endl;
300 cout<<"后续遍历："<<endl;
301 postorder(root->leftChild, Visit);
302 cout<<endl;
303 find = Search(root, x);
304 if(find != NULL)
305 cout<<"数据元素"<<x<<"在二叉树中"<<endl;
306 cout<<" not find x";
307 return 0;
308 Destroy(&root);
309 }