① 急求c语言写二叉树的遍历
BinaryTree.h:
/********************************************************************
created: 2006/07/04
filename: BinaryTree.h
author: 李创
http://www.cppblog.com/converse/
purpose: 演示二叉树的算法
*********************************************************************/
#ifndef BinaryTree_H
#define BinaryTree_H
＃i nclude <stdlib.h>
＃i nclude <stack>
class BinaryTree
{
private:
typedef int Item;
typedef struct TreeNode
{
Item Node;
TreeNode* pRight;
TreeNode* pLeft;
TreeNode(Item node = 0, TreeNode* pright = NULL, TreeNode* pleft = NULL)
: Node(node)
, pRight(pright)
, pLeft(pleft)
{
}
}TreeNode, *PTreeNode;
public:
enum TraverseType
{
PREORDER = 0, // 前序
INORDER = 1, // 中序
POSTORDER = 2, // 后序
LEVELORDER = 3 // 层序
};
BinaryTree(Item Array[], int nLength);
~BinaryTree();
PTreeNode GetRoot()
{
return m_pRoot;
}
// 遍历树的对外接口
// 指定遍历类型和是否是非递归遍历,默认是递归遍历
void Traverse(TraverseType traversetype, bool bRec = true);
private:
PTreeNode CreateTreeImpl(Item Array[], int nLength);
void DetroyTreeImpl(PTreeNode pTreenode);
void PreTraverseImpl(PTreeNode pTreenode); // 递归前序遍历树
void InTraverseImpl(PTreeNode pTreenode); // 递归中序遍历树
void PostTraverseImpl(PTreeNode pTreenode); // 递归后序遍历树
void NoRecPreTraverseImpl(PTreeNode pTreenode); // 非递归前序遍历树
void NoRecInTraverseImpl(PTreeNode pTreenode); // 非递归中序遍历树
void NoRecPostTraverseImpl(PTreeNode pTreenode); // 非递归后序遍历树
void LevelTraverseImpl(PTreeNode pTreenode);
PTreeNode m_pRoot; // 根结点
// 采用STL里面的stack作为模拟保存链表结点的stack容器
typedef std::stack<BinaryTree::PTreeNode> TreeNodeStack;
};
#endif
BinaryTree.cpp:
/********************************************************************
created: 2006/07/04
filename: BinaryTree.cpp
author: 李创
http://www.cppblog.com/converse/
purpose: 演示二叉树的算法
*********************************************************************/
＃i nclude <iostream>
＃i nclude <assert.h>
＃i nclude <queue>
＃i nclude "BinaryTree.h"
BinaryTree::BinaryTree(Item Array[], int nLength)
: m_pRoot(NULL)
{
assert(NULL != Array);
assert(nLength > 0);
m_pRoot = CreateTreeImpl(Array, nLength);
}
BinaryTree::~BinaryTree()
{
DetroyTreeImpl(m_pRoot);
}
// 按照中序递归创建树
BinaryTree::PTreeNode BinaryTree::CreateTreeImpl(Item Array[], int nLength)
{
int mid = nLength / 2;
PTreeNode p = new TreeNode(Array[mid]);
if (nLength > 1)
{
p->pLeft = CreateTreeImpl(Array, nLength / 2);
p->pRight = CreateTreeImpl(Array + mid + 1, nLength / 2 - 1);
}
return p;
}
void BinaryTree::DetroyTreeImpl(PTreeNode pTreenode)
{
if (NULL != pTreenode->pLeft)
{
DetroyTreeImpl(pTreenode->pLeft);
}
if (NULL != pTreenode->pRight)
{
DetroyTreeImpl(pTreenode->pRight);
}
delete pTreenode;
pTreenode = NULL;
}
// 遍历树的对外接口
// 指定遍历类型和是否是非递归遍历,默认是递归遍历
void BinaryTree::Traverse(TraverseType traversetype, bool bRec /*= true*/)
{
switch (traversetype)
{
case PREORDER: // 前序
{
if (true == bRec)
{
std::cout << "递归前序遍历树\n";
PreTraverseImpl(m_pRoot);
}
else
{
std::cout << "非递归前序遍历树\n";
NoRecPreTraverseImpl(m_pRoot);
}
}
break;
case INORDER: // 中序
{
if (true == bRec)
{
std::cout << "递归中序遍历树\n";
InTraverseImpl(m_pRoot);
}
else
{
std::cout << "非递归中序遍历树\n";
NoRecInTraverseImpl(m_pRoot);
}
}
break;
case POSTORDER: // 后序
{
if (true == bRec)
{
std::cout << "递归后序遍历树\n";
PostTraverseImpl(m_pRoot);
}
else
{
std::cout << "非递归后序遍历树\n";
NoRecPostTraverseImpl(m_pRoot);
}
}
break;
case LEVELORDER: // 层序
{
std::cout << "层序遍历树\n";
LevelTraverseImpl(m_pRoot);
}
}
std::cout << std::endl;
}
// 递归前序遍历树
void BinaryTree::PreTraverseImpl(PTreeNode pTreenode)
{
if (NULL == pTreenode)
return;
std::cout << "Item = " << pTreenode->Node << std::endl;
PreTraverseImpl(pTreenode->pLeft);
PreTraverseImpl(pTreenode->pRight);
}
// 非递归前序遍历树
void BinaryTree::NoRecPreTraverseImpl(PTreeNode pTreenode)
{
if (NULL == pTreenode)
return;
TreeNodeStack NodeStack;
PTreeNode pNode;
NodeStack.push(pTreenode);
while (!NodeStack.empty())
{
while (NULL != (pNode = NodeStack.top())) // 向左走到尽头
{
std::cout << "Item = " << pNode->Node << std::endl; // 访问当前结点
NodeStack.push(pNode->pLeft); // 左子树根结点入栈
}
NodeStack.pop(); // 左子树根结点退
栈
if (!NodeStack.empty())
{
pNode = NodeStack.top();
NodeStack.pop(); // 当前结点退栈
NodeStack.push(pNode->pRight); // 当前结点的右子树根结点入栈
}
}
}
// 中序遍历树
// 中序遍历输出的结果应该和用来初始化树的数组的排列顺序一致
void BinaryTree::InTraverseImpl(PTreeNode pTreenode)
{
if (NULL == pTreenode)
return;
if (NULL != pTreenode->pLeft)
{
InTraverseImpl(pTreenode->pLeft);
}
std::cout << "Item = " << pTreenode->Node << std::endl;
if (NULL != pTreenode->pRight)
{
InTraverseImpl(pTreenode->pRight);
}
}
// 非递归中序遍历树
void BinaryTree::NoRecInTraverseImpl(PTreeNode pTreenode)
{
if (NULL == pTreenode)
return;
TreeNodeStack NodeStack;
PTreeNode pNode;
NodeStack.push(pTreenode);
while (!NodeStack.empty())
{
while (NULL != (pNode = NodeStack.top())) // 向左走到尽头
{
NodeStack.push(pNode->pLeft);
}
NodeStack.pop();
if (!NodeStack.empty() && NULL != (pNode = NodeStack.top()))
{
std::cout << "Item = " << pNode->Node << std::endl;
NodeStack.pop();
NodeStack.push(pNode->pRight);
}
}
}
// 后序遍历树
void BinaryTree::PostTraverseImpl(PTreeNode pTreenode)
{
if (NULL == pTreenode)
return;
if (NULL != pTreenode->pLeft)
{
PostTraverseImpl(pTreenode->pLeft);
}
if (NULL != pTreenode->pRight)
{
PostTraverseImpl(pTreenode->pRight);
}
std::cout << "Item = " << pTreenode->Node << std::endl;
}
// 非递归后序遍历树
void BinaryTree::NoRecPostTraverseImpl(PTreeNode pTreenode)
{
if (NULL == pTreenode)
return;
TreeNodeStack NodeStack;
PTreeNode pNode1, pNode2;
NodeStack.push(pTreenode);
pNode1 = pTreenode->pLeft;
bool bVisitRoot = false; // 标志位,是否访问过根结点
while (!NodeStack.empty())
{
while (NULL != pNode1) // 向左走到尽头
{
NodeStack.push(pNode1);
pNode1 = pNode1->pLeft;
}
pNode1 = NodeStack.top();
NodeStack.pop();
if (NULL == pNode1->pRight) // 如果没有右子树就是叶子结点
{
std::cout << "Item = " << pNode1->Node << std::endl;
pNode2 = pNode1;
pNode1 = NodeStack.top();
if (pNode2 == pNode1->pRight) // 如果这个叶子结点是右子树
{
std::cout << "Item = " << pNode1->Node << std::endl;
NodeStack.pop();
pNode1 = NULL;
}
else // 否则访问右子树
{
pNode1 = pNode1->pRight;
}
}
else // 访问右子树
{
if (pNode1 == pTreenode && true == bVisitRoot) // 如果已经访问过右子树那么就退出
{
std::cout << "Item = " << pNode1->Node << std::endl;
return;
}
else
{
if (pNode1 == pTreenode)
{
bVisitRoot = true;
}
NodeStack.push(pNode1);
pNode1 = pNode1->pRight;
}
}
}
}
// 按照树的层次从左到右访问树的结点
void BinaryTree::LevelTraverseImpl(PTreeNode pTreenode)
{
if (NULL == pTreenode)
return;
// 层序遍历用于保存结点的容器是队列
std::queue<PTreeNode> NodeQueue;
PTreeNode pNode;
NodeQueue.push(pTreenode);
while (!NodeQueue.empty())
{
pNode = NodeQueue.front();
NodeQueue.pop();
std::cout << "Item = " << pNode->Node << std::endl;
if (NULL != pNode->pLeft)
{
NodeQueue.push(pNode->pLeft);
}
if (NULL != pNode->pRight)
{
NodeQueue.push(pNode->pRight);
}
}
}
main.cpp
/********************************************************************
created: 2006/07/04
filename: main.cpp
author: 李创
http://www.cppblog.com/converse/
purpose: 测试二叉树的算法
*********************************************************************/
＃i nclude "BinaryTree.h"
＃i nclude <stdio.h>
＃i nclude <stdlib.h>
＃i nclude <time.h>
＃i nclude <iostream>
void DisplayArray(int array[], int length)
{
int i;
for (i = 0; i < length; i++)
{
printf("array[%d] = %d\n", i, array[i]);
}
}
void CreateNewArray(int array[], int length)
{
for (int i = 0; i < length; i++)
{
array[i] = rand() % 256 + i;
}
}
int main()
{
int array[10];
srand(time(NULL));
// 创建数组
CreateNewArray(array, 10);
DisplayArray(array, 10);
BinaryTree *pTree = new BinaryTree(array, 10);
// 测试前序遍历
pTree->Traverse(BinaryTree::PREORDER);
std::cout << "root = " << pTree->GetRoot()->Node << std::endl;
std::cout << "root->left = " << pTree->GetRoot()->pLeft->Node << std::endl;
std::cout << "root->right = " << pTree->GetRoot()->pRight->Node << std::endl;
pTree->Traverse(BinaryTree::PREORDER, false);
// 测试中序遍历
pTree->Traverse(BinaryTree::INORDER);
std::cout << "root = " << pTree->GetRoot()->Node << std::endl;
std::cout << "root->left = " << pTree->GetRoot()->pLeft->Node << std::endl;
std::cout << "root->right = " << pTree->GetRoot()->pRight->Node << std::endl;
pTree->Traverse(BinaryTree::INORDER, false);
// 测试后序遍历
pTree->Traverse(BinaryTree::POSTORDER);
std::cout << "root = " << pTree->GetRoot()->Node << std::endl;
std::cout << "root->left = " << pTree->GetRoot()->pLeft->Node << std::endl;
std::cout << "root->right = " << pTree->GetRoot()->pRight->Node << std::endl;
pTree->Traverse(BinaryTree::POSTORDER, false);
// 测试层序遍历
pTree->Traverse(BinaryTree::LEVELORDER);
system("pause");
delete pTree;
return 0;
}
② 二叉树的层次遍历算法
二叉树的层次遍历算法有如下三种方法：
给定一棵二叉树，要求进行分层遍历，每层的节点值单独打印一行，下图给出事例结构：
之后大家就可以自己画图了，下面给出程序代码：
[cpp] view plain
void print_by_level_3(Tree T) {
vector<tree_node_t*> vec;
vec.push_back(T);
int cur = 0;
int end = 1;
while (cur < vec.size()) {
end = vec.size();
while (cur < end) {
cout << vec[cur]->data << " ";
if (vec[cur]->lchild)
vec.push_back(vec[cur]->lchild);
if (vec[cur]->rchild)
vec.push_back(vec[cur]->rchild);
cur++;
}
cout << endl;
}
}
最后给出完成代码的测试用例：124##57##8##3#6##
[cpp] view plain
#include<iostream>
#include<vector>
#include<deque>
using namespace std;
typedef struct tree_node_s {
char data;
struct tree_node_s *lchild;
struct tree_node_s *rchild;
}tree_node_t, *Tree;
void create_tree(Tree *T) {
char c = getchar();
if (c == '#') {
*T = NULL;
} else {
*T = (tree_node_t*)malloc(sizeof(tree_node_t));
(*T)->data = c;
create_tree(&(*T)->lchild);
create_tree(&(*T)->rchild);
}
}
void print_tree(Tree T) {
if (T) {
cout << T->data << " ";
print_tree(T->lchild);
print_tree(T->rchild);
}
}
int print_at_level(Tree T, int level) {
if (!T || level < 0)
return 0;
if (0 == level) {
cout << T->data << " ";
return 1;
}
return print_at_level(T->lchild, level - 1) + print_at_level(T->rchild, level - 1);
}
void print_by_level_1(Tree T) {
int i = 0;
for (i = 0; ; i++) {
if (!print_at_level(T, i))
break;
}
cout << endl;
}
void print_by_level_2(Tree T) {
deque<tree_node_t*> q_first, q_second;
q_first.push_back(T);
while(!q_first.empty()) {
while (!q_first.empty()) {
tree_node_t *temp = q_first.front();
q_first.pop_front();
cout << temp->data << " ";
if (temp->lchild)
q_second.push_back(temp->lchild);
if (temp->rchild)
q_second.push_back(temp->rchild);
}
cout << endl;
q_first.swap(q_second);
}
}
void print_by_level_3(Tree T) {
vector<tree_node_t*> vec;
vec.push_back(T);
int cur = 0;
int end = 1;
while (cur < vec.size()) {
end = vec.size();
while (cur < end) {
cout << vec[cur]->data << " ";
if (vec[cur]->lchild)
vec.push_back(vec[cur]->lchild);
if (vec[cur]->rchild)
vec.push_back(vec[cur]->rchild);
cur++;
}
cout << endl;
}
}
int main(int argc, char *argv[]) {
Tree T = NULL;
create_tree(&T);
print_tree(T);
cout << endl;
print_by_level_3(T);
cin.get();
cin.get();
return 0;
}
③ 二叉树的层次遍历是递归的算法吗
层次遍历从方法上不具有递归的形式，所以一般不用递归实现。当然了，非要写成递归肯定也是可以的，大致方法如下。 void LevelOrder(BTree T, int cnt) { BTree level = malloc(sizeof(struct BTNode)*cnt); if(level==NULL) return; int i=0,rear=0; if(cnt==0) return; for(i=0; i<cnt; i++){ printf("%c ",T[i].data); if(T[i].lchild) level[rear++]=*T[i].lchild; if(T[i].rchild) level[rear++]=*T[i].rchild; } printf("\n"); LevelOrder(level, rear); free(level); } 补充一下，在main里面调用的时候就得用LevelOrder(T,1)了。
④ 二叉树遍历，递归与非递归，前序中序后序遍历,C代码
#include<stdio.h>
#include<stdlib.h>
typedef struct bitnode
{
char data;
struct bitnode *lchild,*rchild;
}bitnode,*bitree;//二叉树节点类型和节点指针类型
bitree create()//先序创建
{
bitree root=NULL;
char c;
scanf("%c",&c);
fflush(stdin);
if(c=='#')return NULL;
else
{
root=(bitnode*)malloc(sizeof(bitnode));
root->data=c;
root->lchild=create();
root->rchild=create();
}
return root;
}
void preorder(bitree root)//先根遍历
{
if(!root)return;
else
{
putchar(root->data);
preorder(root->lchild);
preorder(root->rchild);
}
}
void inorder(bitree root)//中根遍历
{
if(!root)return;
else
{
inorder(root->lchild);
putchar(root->data);
inorder(root->rchild);
}
}
void postorder(bitree root)//后根遍历
{
if(!root)return;
else
{
postorder(root->lchild);
postorder(root->rchild);
putchar(root->data);
}
}
int leafcount(bitree root)//计算叶子节点
{
if(!root)return 0;
else
{
if(!root->lchild&&!root->rchild)return 1;
else return leafcount(root->lchild)+leafcount(root->rchild);
}
}
int depth(bitree root)//树的高度
{
if(!root)return 0;
else
{
int m=depth(root->lchild);
int n=depth(root->rchild);
return (m>n?m:n)+1;
}
}
void Revolute(bitree root)// 交换左右子树
{
bitree t;
t=root->lchild;
root->lchild=root->rchild;
root->rchild=t;
if(root->lchild)Revolute(root->lchild);
if(root->rchild)Revolute(root->rchild);
}
void main()
{
bitree root=NULL;
printf("输入先序序列：\n");
root=create();
printf("前序遍历：\n");
preorder(root);
printf("\n");
printf("中序遍历：\n");
inorder(root);
printf("\n");
printf("后序遍历：\n");
postorder(root);
printf("\n");
printf("二叉树的叶子结点个数为:%d\n",leafcount(root));
printf("二叉树的高度为:%d\n",depth(root));
printf("交换左右子树后\n");
Revolute(root);
printf("前序遍历：\n");
preorder(root);
printf("\n");
printf("中序遍历：\n");
inorder(root);
printf("\n");
printf("后序遍历：\n");
postorder(root);
printf("\n");
}
/*输入序列为前序序列，#代表空
例如二叉树为
--------a
-------/-\
------b---c
-----/-\
----d---e
输入abd##e##c##(每次输入一个字符回车)*/
⑤ 如何用C语言实现层次遍历二叉树
下面是c语言的前序遍历二叉树的算法，在这里假设的节点元素值假设的为字符型，
说明：算法中用到了结构体，也用到了递归的方法，你看看怎么样，祝你好运！
#include"stdio.h"
typedef
char
elemtype;
typedef
struct
node
//定义链表结构
{
elemtype
data;
//定义节点值
struct
note
*lchild;
//定义左子节点值
struct
note
*rchild;
//定义右节点值
}btree;
preorder(btree
*root)
//前序遍历
{
if(roof!=null)
//如果不是空节点
{
printf("%c\n",root->data);
//输出当前节点
preorder(root->lchild);
//递归前序遍历左子节点
preorder(root->rchild);
//递归前序遍历右子节点
}
return;
//结束
}
⑥ 用c语言实现二叉树的程序，可以输入输出和遍历
#include <stdio.h>
#include <stdlib.h>
#include <iostream.h>
const int MaxLength=10;//结点个数不超过10个
typedef struct tree
{
char data;
struct tree *lchild,*rchild;
}tree;
//先序递归 建立二叉树
void Createbitree(tree* &T)
{
char ch;
ch=getchar();
if(ch=='#')
T=NULL;
else
{
T=(tree*)malloc(sizeof(tree));
T->data =ch;
Createbitree(T->lchild );
Createbitree(T->rchild );
}
}
//先序递归遍历
void PreOrderTraverse(tree* T)
{
if(T)
{
cout<<T->data;
PreOrderTraverse(T->lchild);
PreOrderTraverse(T->rchild);
}
}
//中序递归遍历
void InOrderTraverse(tree* T)
{
if(T)
{
InOrderTraverse(T->lchild);
cout<<T->data;
InOrderTraverse(T->rchild);
}
}
void PostOrderTraverse(tree* T)
{
if(T)
{
PostOrderTraverse(T->lchild);
PostOrderTraverse(T->rchild);
cout<<T->data;
}
}
//层序遍历
void LevelOrderTraverse(tree* T)
{
tree* Q[MaxLength];
int front=0,rear=0;
tree* p;
if(T)//根结点入队
{
Q[rear]=T;
rear=(rear+1)%MaxLength;
}
while(front!=rear)
{
p=Q[front]; //队头元素出队
front=(front+1)%MaxLength;
cout<<p->data;
if(p->lchild)//左孩子不为空，入队
{
Q[rear]=p->lchild;
rear=(rear+1)%MaxLength;
}
if(p->rchild)//右孩子不为空，入队
{
Q[rear]=p->rchild;
rear=(rear+1)%MaxLength;
}
}
}
//主函数
void main()
{
cout<<"请按先序次序输入二叉树的数据:"<<endl;
tree* T;
Createbitree(T);
cout<<"二叉树的先序序列为:"<<endl;
PreOrderTraverse(T);
cout<<endl<<"二叉树的中序序列为:"<<endl;
InOrderTraverse(T);
cout<<endl<<"二叉树的后序序列为:"<<endl;
PostOrderTraverse(T);
cout<<endl<<"二叉树的层序序列为:"<<endl;
LevelOrderTraverse(T);
cout<<endl;
}
比如 1
2 3
4 5 6 7
按先序输入是124##5##36##7##
⑦ c语言编程:建立二叉树,层序/先序遍历
#include<stdio.h>
#include<stdlib.h>
typedef struct BiT{
char data;
struct BiT *lchild;
struct BiT *rchild;
}BiT;
BiT* CreateBiTree(BiT *T) {
//构造二叉链表表示的二叉树T
char ch;
scanf("%c",&ch);
if (ch=='#') T = NULL;
else {
T = (BiT *)malloc(sizeof(BiT));
T->data = ch;
T->lchild=CreateBiTree(T->lchild);
T->rchild=CreateBiTree(T->rchild);
}
return T;
}
void PreOrderTraverse(BiT *T) {
// 先序遍历二叉树T
if (T) {
printf("%c",T->data);
PreOrderTraverse(T->lchild);
PreOrderTraverse(T->rchild);
}
}
void InOrderTraverse(BiT *T) {
// 中序遍历二叉树T
if (T) {
InOrderTraverse(T->lchild);
printf("%c",T->data);
InOrderTraverse(T->rchild);
}
}
void PostOrderTraverse(BiT *T) {
// 后序遍历二叉树T
if (T) {
PostOrderTraverse(T->lchild);
PostOrderTraverse(T->rchild);
printf("%c",T->data);
}
}
void main() {
printf("先序建树:");
BiT *T=CreateBiTree(T);
printf("\n先序遍历:");
PreOrderTraverse(T);
printf("\n中序遍历:");
InOrderTraverse(T);
printf("\n后序遍历:");
PostOrderTraverse(T);
getchar();getchar();
}