user-0 提问: C语言数据结构二叉树

回复:
user: user-1
content: #include "head.h" typedef  int DataType;  typedef struct tree{ 	DataType num; 	struct tree *left_child; 	struct tree *right_child; }node;  node * init_tree(void) { 	node *root = (node *)malloc(sizeof(node)); 	(node *)memset(root, 0x00, sizeof(node)); 	 	root->left_child = NULL; 	root->right_child = NULL; 	 	return root; }  void insert_tree(node **root) { 	static node *last_node = NULL; 	 	if(*root != NULL){ 		fprintf(stderr, "%s\012", "Here is not empty !"); 		return; 	} 	node *rt = (node *)calloc(1, sizeof(node)); 	*root = rt; 	if(!last_node){ 		system("color 0C"); 		fprintf(stderr, "%s\012", "\"The data inserted into the root node .\""); 		Sleep(2000); 		system("color 0A"); 	} 	printf("Enter to insert data :"); 	while(scanf("%d", &rt->num) == 0){ 		fflush(stdin); 		fprintf(stderr, "%s", "Illegal input and input again :"); 	} 	rt->left_child = NULL; 	rt->right_child = NULL; 	 	system("color 0C"); 	fprintf(stderr, "%s", "\n\t-----------------------------------------\n"); 	fprintf(stderr, "%s\n", "\t1.insert left_child  2.insert right_child\n\ 	3.insert brother     0.end_insert"); 	fprintf(stderr, "%s", "\t-----------------------------------------\n\n"); 	Sleep(3000); 	system("color 0A"); 	int choose; 	lb: fprintf(stderr, "%s", "Please select a :"); 	while(scanf("%d", &choose) == 0){ 		fflush(stdin); 		fprintf(stderr, "%s", "Illegal input and input again :"); 	} 	if(choose > 3 || choose < 0){ 		fprintf(stderr, "%s", "There is no this option.\012"); 		goto lb; 	}	 	 	switch(choose){ 		case 1:{ 			last_node = rt; 			insert_tree(&rt->left_child); 		}break; 		 		case 2:{ 			last_node = rt; 			insert_tree(&rt->right_child); 		}break; 		 		case 3:{ 			if(last_node != NULL){ 				if(last_node->left_child != NULL && last_node->right_child != NULL) 					fprintf(stderr, "%s", "Have no place to insert .\012"); 				 				else if(last_node->left_child == NULL) 					insert_tree(&last_node->left_child); 				 				else 					insert_tree(&last_node->right_child); 			} 	 		}break; 		case 4:{ 			 		}break; 		 		case 0: 			return; 	} 	 }  void preorder(node **p) { 	if(*p == NULL) 		return; 	fprintf(stderr, "%d ",(*p)->num); 	preorder(&(*p)->left_child); 	preorder(&(*p)->right_child); 	 }  void inorder(node **p) { 	if(*p == NULL) 		return; 	inorder(&(*p)->left_child); 	fprintf(stderr, "%d ",(*p)->num); 	inorder(&(*p)->right_child); 	 }  void postorder(node **p) { 	if(*p == NULL) 		return; 	inorder(&(*p)->left_child); 	inorder(&(*p)->right_child); 	fprintf(stderr, "%d ",(*p)->num); 	 }  void show(node **root) { 	node *p = *root; 	char order; 	fflush(stdin); 	lb2:system("color 0C"); 	fprintf(stderr, "%s", "\n\t--------------------------------------\n"); 	fprintf(stderr, "%s", "\tb:PreOrder i:Inorder a:PostOrder e:end\012"); 	fprintf(stderr, "%s", "\t--------------------------------------\n\n"); 	Sleep(3000); 	system("color 0A"); 	fprintf(stderr, "%s", "Choose the way to traverse :"); 	while(scanf("%c", &order) != '\n'){ 		fflush(stdin); 		switch(order){ 			case 'b': 				fprintf(stderr, "%s", "For the former sequence traversal results:"); 				preorder(&p); 				fprintf(stderr, "%c", '\012'); 				goto lb2; 				break; 		 			case 'i': 				fprintf(stderr, "%s", "In order to traverse the results :"); 				inorder(&p); 				fprintf(stderr, "%c", '\012'); 				goto lb2; 				break; 		 			case 'a': 				fprintf(stderr, "%s", "After the sequence traversal results for: \ "); 				postorder(&p); 				fprintf(stderr, "%c", '\012'); 				goto lb2; 				break; 				 			case 'e': 				return; 				 			default:{ 				fprintf(stderr, "%s", "There is no this option.\012"); 				goto lb2; 			} 		} 		 	}  }  node * creat_tree(void) { 	node *root = init_tree(); 	insert_tree(&root->left_child); 	show(&root->left_child); 	 	return root; }

user: user-2
content: 无非是先序 中序 后序

user: user-3
content: 仅供参考：#include <iostream> #include <stack> #include <queue> #include <locale.h> using namespace std; typedef struct BiTNode {//二叉树结点     char data;                      //数据     struct BiTNode *lchild,*rchild; //左右孩子指针 } BiTNode,*BiTree; int CreateBiTree(BiTree &T) {//按先序序列创建二叉树     char data;     scanf("%c",&data);//按先序次序输入二叉树中结点的值（一个字符），‘#’表示空树     if (data == '#') {         T = NULL;     } else {         T = (BiTree)malloc(sizeof(BiTNode));         T->data = data;         //生成根结点         CreateBiTree(T->lchild);//构造左子树         CreateBiTree(T->rchild);//构造右子树     }     return 0; } void Visit(BiTree T) {//输出     if (T->data != '#') {         printf("%c ",T->data);     } } void PreOrder(BiTree T) {//先序遍历     if (T != NULL) {         Visit(T);               //访问根节点         PreOrder(T->lchild);    //访问左子结点         PreOrder(T->rchild);    //访问右子结点     } } void InOrder(BiTree T) {//中序遍历     if (T != NULL) {         InOrder(T->lchild);     //访问左子结点         Visit(T);               //访问根节点         InOrder(T->rchild);     //访问右子结点     } } void PostOrder(BiTree T) {//后序遍历     if (T != NULL) {         PostOrder(T->lchild);   //访问左子结点         PostOrder(T->rchild);   //访问右子结点         Visit(T);               //访问根节点     } } void PreOrder2(BiTree T) {//先序遍历(非递归) //访问T->data后，将T入栈，遍历左子树；遍历完左子树返回时，栈顶元素应为T，出栈，再先序遍历T的右子树。     stack<BiTree> stack;     BiTree p = T;//p是遍历指针     while (p || !stack.empty()) {   //栈不空或者p不空时循环         if (p != NULL) {             stack.push(p);          //存入栈中             printf("%c ",p->data);  //访问根节点             p = p->lchild;          //遍历左子树         } else {             p = stack.top();        //退栈             stack.pop();             p = p->rchild;          //访问右子树         }     } } void InOrder2(BiTree T) {//中序遍历(非递归) //T是要遍历树的根指针，中序遍历要求在遍历完左子树后，访问根，再遍历右子树。 //先将T入栈，遍历左子树；遍历完左子树返回时，栈顶元素应为T，出栈，访问T->data，再中序遍历T的右子树。     stack<BiTree> stack;     BiTree p = T;//p是遍历指针     while (p || !stack.empty()) {   //栈不空或者p不空时循环         if (p != NULL) {             stack.push(p);          //存入栈中             p = p->lchild;          //遍历左子树         } else {             p = stack.top();        //退栈，访问根节点             printf("%c ",p->data);             stack.pop();             p = p->rchild;          //访问右子树         }     } }  typedef struct BiTNodePost{     BiTree biTree;     char tag; } BiTNodePost,*BiTreePost; void PostOrder2(BiTree T) {//后序遍历(非递归)     stack<BiTreePost> stack;     BiTree p = T;//p是遍历指针     BiTreePost BT;     while (p != NULL || !stack.empty()) {//栈不空或者p不空时循环         while (p != NULL) {//遍历左子树             BT = (BiTreePost)malloc(sizeof(BiTNodePost));             BT->biTree = p;             BT->tag = 'L';//访问过左子树             stack.push(BT);             p = p->lchild;         }         while (!stack.empty() && (stack.top())->tag == 'R') {//左右子树访问完毕访问根节点             BT = stack.top();             stack.pop();//退栈             printf("%c ",BT->biTree->data);         }         if (!stack.empty()) {//遍历右子树             BT = stack.top();             BT->tag = 'R';//访问过右子树             p = BT->biTree;             p = p->rchild;         }     } }  void LevelOrder(BiTree T) {//层次遍历     if (T == NULL) return;     BiTree p = T;     queue<BiTree> queue;//队列     queue.push(p);//根节点入队     while (!queue.empty()) {    //队列不空循环         p = queue.front();      //对头元素出队         printf("%c ",p->data);  //访问p指向的结点         queue.pop();            //退出队列         if (p->lchild != NULL) {//左子树不空，将左子树入队             queue.push(p->lchild);         }         if (p->rchild != NULL) {//右子树不空，将右子树入队             queue.push(p->rchild);         }     } } int main() {     BiTree T;      setlocale(LC_ALL,"chs");     CreateBiTree(T);      printf("先序遍历        ：");PreOrder  (T);printf("\n");     printf("先序遍历(非递归)：");PreOrder2 (T);printf("\n");                                                printf("\n");     printf("中序遍历        ：");InOrder   (T);printf("\n");     printf("中序遍历(非递归)：");InOrder2  (T);printf("\n");                                                printf("\n");     printf("后序遍历        ：");PostOrder (T);printf("\n");     printf("后序遍历(非递归)：");PostOrder2(T);printf("\n");                                                printf("\n");     printf("层次遍历        ：");LevelOrder(T);printf("\n");      return 0; } //ABC##DE#G##F### //先序遍历        ：A B C D E G F //先序遍历(非递归)：A B C D E G F // //中序遍历        ：C B E G D F A //中序遍历(非递归)：C B E G D F A // //后序遍历        ：C G E F D B A //后序遍历(非递归)：C G E F D B A // //层次遍历        ：A B C D E F G //  ///       A ///      / ///     B ///    / \ ///   C   D ///      / \ ///     E   F ///      \ ///       G