简单二叉树相关代码

Posted 2020-11-05 CHRIS-ZSY

  1 #include <stdio.h>
  2 
  3 typedef struct tagBinaryTree* Node;
  4 typedef struct tagBinaryTree BinaryTree;
  5 
  6 struct tagBinaryTree{
  7     int key;
  8     Node lchild;
  9     Node rchild;
 10     Node parent;
 11 };
 12 typedef struct                          //定义栈的结构体 
 13 { 
 14     Node          *base;              //在栈构造前和销毁后，base的值为NULL 
 15     Node          *top;               //栈顶指针 
 16     int             stacksize;          //当前已分配的存储空间，以元素为单位 
 17 }Stack; 
 18 int Key(Node branch)
 19 {
 20     if(branch == NULL) return 0;
 21     return branch->key;
 22 }
 23 
 24 Node Left(Node branch)
 25 {
 26     if(branch == NULL) return NULL;
 27     return branch->lchild;
 28 }
 29 
 30 Node Right(Node branch)
 31 {
 32     if(branch == NULL) return NULL;
 33     return branch->rchild;
 34 }
 35 
 36 Node Parent(Node branch)
 37 {
 38     if(branch == NULL) return NULL;
 39     return branch->parent;
 40 }
 41 Node LookUp(Node T, int key)
 42 {
 43     while(T != NULL && Key(T) != key){
 44         if(key < Key(T)){
 45             T = Left(T);
 46         }else{
 47             T = Right(T);
 48         }
 49     }
 50     return T;
 51 }
 52 Node CreateLeaf(int x, Node* T)
 53 {
 54     Node n = malloc(sizeof(BinaryTree));
 55     n->lchild = n->rchild = n->parent = NULL;
 56     
 57     n->key = x;
 58     *T = n;
 59     return n;
 60 }
 61 
 62 int InsertKey(int key, Node* T)
 63 {
 64     Node root = *T,parent = NULL,x = NULL;
 65     x = LookUp(*T, key);
 66     if(x != NULL) return 0;
 67     CreateLeaf(key, &x);
 68     
 69     while(root != NULL){
 70         parent = root;
 71         if(key < Key(root)){
 72             root = Left(root);
 73         }else if(key > Key(root)){
 74             root = Right(root);
 75         }else{
 76             return 0;
 77         }
 78     }
 79     x->parent = parent;
 80 
 81     if(parent == NULL) {
 82         *T = x;
 83         return 0;
 84     }else if(key < Key(parent)){
 85         parent->lchild = x;
 86     }else{
 87         parent->rchild= x;
 88     }
 89     return 0;
 90 }
 91 
 92 int PreOrderTravel(Node T, Stack S)
 93 {
 94     while( S.base != S.top|| T != NULL)       //判断栈和树是否为空 
 95     { 
 96         while( T !=NULL )                  //向左子树一直循环到最左的节点 
 97         { 
 98             printf("%d ",T->key);      //输出元素
 99             *S.top++ = T; 
100             T = T->lchild; 
101         } 
102         T = *--S.top;                     //实现出栈 
103         T = T->rchild;                    //转向右子树 
104     } 
105     printf("\n");
106     return 0; 
107 }
108 int InOder(Node T,Stack S)      //实现非递归中序遍历函数 
109 { 
110     while( S.base != S.top || T != NULL)       //判断栈和树是否为空 
111     { 
112         while(T!=NULL)                  //向左子树一直循环到最左的节点 
113         { 
114             *S.top++ = T; 
115             T = T->lchild; 
116         } 
117         T = *--S.top;                     //实现出栈 
118         printf("%d ", T->key);
119         T = T->rchild;                  //转向右子树 
120     } 
121     printf("\n");
122     return 0; 
123 } 
124         
125 int PostOrder(Node T,Stack S)   //实现非递归后序遍历函数 
126 { 
127     Node temp=NULL;                   //定义临时变量，用来标记刚刚访问过的节点 
128     while( S.base != S.top || T!= NULL )      //判断栈和树是否为空 
129     { 
130         while(T!=NULL)                  //向左子树一直循环到最左的节点 
131         { 
132             *S.top++ = T; 
133             T = T->lchild; 
134         } 
135         T = *(S.top-1);                   //取栈顶节点 
136         if( T->rchild == NULL || T->rchild == temp) 
137         {                               //如果该节点没有右孩子或者其右孩子刚刚被访问过 
138             printf("%d ",T->key);      //输出元素
139             S.top--;                    //已访问，使其出栈 
140             temp=T;                     //标记为刚刚访问过 
141             T=NULL;                     //若遍历完以该节点为根的子树，且栈空，则结束，否则继续 
142         } else{
143             T = T->rchild;                    //转向右子树 
144         }
145     } 
146     printf("\n");
147     return 0; 
148 } 
149 int CreatStack(Stack* S)             //实现栈的建立函数 
150 { 
151     S->base=(Node*)malloc(100*sizeof(Node)); 
152     if(!S->base)                         //判断是否建立失败 
153         return -1; 
154     S->top=S->base; 
155     S->stacksize=100; 
156     return 0; 
157 }
158 void DestoryStack(Stack* s)
159 {
160     if(!s || !s->base){
161         return ;
162     }
163     free(s->base);
164     memset(s, 0, sizeof(Stack));
165 }
166 Node FollowNode(Node T, int key)
167 {
168     Node cur = LookUp(T, key);
169     
170     if(cur->rchild){
171         Node right = cur->rchild;
172         while(right->lchild != NULL){
173             right = right->lchild;
174         }
175         return right;
176     }else if(Parent(cur)){
177         Node parent= Parent(cur);
178         while(parent != NULL && Right(parent) == cur ){
179             cur=parent;
180             parent = Parent(parent);
181         }
182         return parent;
183     }
184     return NULL;
185 }
186 
187 Node PreNode(Node T, int key)
188 {
189     Node cur = LookUp(T, key);
190     if(cur->lchild){
191         Node left = cur->lchild;
192         while(left->rchild != NULL){
193             left = left->rchild;
194         }
195         return left;
196     }else if(Parent(cur)){
197         Node parent = Parent(cur);
198         while(parent != NULL && Left(parent) == cur){
199             cur = parent;
200             parent = Parent(parent);
201         }
202         return parent;
203     }
204     return NULL;
205 }
206 Node DeleteNode(Node* T, int key)
207 {
208     Node cur = LookUp(*T, key);
209     Node root = *T,old_cur = cur,  parent = NULL;
210     
211     if(root == NULL || cur == NULL){
212         return *T;
213     }
214     parent = cur->parent;
215     if(cur->lchild == NULL){
216         cur = cur->rchild;
217     }else if(cur->rchild == NULL){
218         cur = cur->lchild;
219     }else{
220         Node right = cur->rchild;
221         while(right->lchild != NULL){
222             right = right->lchild;
223         }
224         cur->key = right->key;
225         if(right->parent != cur){
226             right->parent->lchild = right->rchild;
227             if(right->rchild != NULL){
228                 right->rchild->parent = right->parent;
229             }
230         }else{
231             cur->rchild = right->rchild;
232             if(right->rchild != NULL){
233                 right->rchild->parent = right->parent;
234             }
235         }
236         free(right);
237         right = NULL;
238         return root;
239     }
240     if(cur != NULL){
241         cur->parent = parent;
242     }else{
243         //printf("cur is NULL\n");
244     }
245     if(root == old_cur && root->lchild == NULL && root->rchild == NULL){
246         *T = NULL;
247         //do nothing
248     }else if(parent == NULL){
249         *T =root = cur;
250     }else{
251         if(parent->lchild == old_cur){
252             parent->lchild = cur;
253         }else{
254             parent->rchild = cur;
255         }
256     }
257     free(old_cur);
258     old_cur = NULL;
259     return root;
260 }
261 
262 int main(int argc, char** argv)
263 {
264     Node root = NULL, pNode = NULL;
265     Stack stack = {0};
266     int len = 0, i = 0;
267     unsigned int tdata[21] = {30, 11, 71, 15, 9, 31, 12, 24, 18,10, 3,13, 14,33,80, 47,8,5,6,26};
268     CreatStack(&stack);
269 
270     while(i < 20){
271         InsertKey(tdata[i], &root);
272         i++;
273     }
274     
275     PreOrderTravel(root, stack);
276     InOder(root,stack);
277     PostOrder(root,stack);
278     
279     pNode = FollowNode(root, 30);
280     printf("30 follow node:%d\n", pNode->key);
281     pNode = PreNode(root, 47);
282     printf("47 pre node :%d\n", pNode->key);
283     DeleteNode(&root, 31);
284 
285     PreOrderTravel(root, stack);
286     InOder(root,stack);
287     PostOrder(root,stack);
288     pNode = FollowNode(root, 30);
289     printf("30 follow node:%d\n", pNode->key);
290     pNode = PreNode(root, 47);
291     printf("47 pre node :%d\n", pNode->key);
292     
293     i = 0;
294     while(i < 20){
295         DeleteNode(&root, tdata[i]);
296         i++;
297     }
298     DestoryStack(&stack);
299     return 0;
300 }