C语言二叉树的遍历。

二叉树的前中后遍历（递归与非递归）
#include
#include

typedef struct NODE
{
char value;
struct NODE *LChild;
struct NODE *RChild;
}BiTNode,*BiTree; //二叉树数据结构
BiTree root;
typedef struct node
{
BiTNode *pointer;
struct node *link;
}LinkStackNode,*LinkStack; //链栈数据结构
LinkStack S;
int count = 0;
//BiTNode * InitTree(BiTree Tree);
BiTNode *CreateTree(BiTree Tree); //创建二叉树
void PreOrder(BiTree Tree); //递归前序遍历二叉树
void MidOrder(BiTree Tree); //递归中序遍历二叉树
void PostOrder(BiTree Tree); //递归后序遍历二叉树
void NPreOrder(BiTree Tree); //非递归前序遍历二叉树
void NMidOrder(BiTree Tree); //非递归中序遍历二叉树
void NPostOrder(BiTree Tree); //非递归后序遍历二叉树
//---------------------------------------------------
LinkStackNode *InitLinkStack(LinkStack top); //初始化链栈
void Push(LinkStack top,BiTNode *p); //进栈操作
BiTNode * Pop(LinkStack top); //出栈操作
//int IsEmpty(LinkStack S); //判断栈是否为空
void main()
{
//BiTree tree;
//root = InitTree(tree);
root = CreateTree(root);
PreOrder(root);
printf("\n");
MidOrder(root);
printf("\n");
PostOrder(root);
printf("\n");
NPreOrder(root);
printf("\n");
NMidOrder(root);
printf("\n");
NPostOrder(root);
printf("\n");
}

/*BiTNode * InitTree(BiTree Tree)
{
//BiTNode *root;
//root = Tree;
Tree = (BiTNode *)malloc(sizeof(BiTNode));
Tree = NULL;
//Tree->LChild = NULL;
//Tree->RChild = NULL;
return Tree;
}*/

//二叉树的扩展先序遍历的创建
BiTNode * CreateTree(BiTree Tree)
{
char ch;
ch = getchar();
if(ch == '.')
Tree = NULL;
else
{
Tree = (BiTNode *)malloc(sizeof(BiTNode));
if(Tree)
{
Tree->value = ch;
Tree->LChild = CreateTree(Tree->LChild);
Tree->RChild = CreateTree(Tree->RChild);
}
}
return Tree;
}

//递归前序遍历二叉树
void PreOrder(BiTree Tree)
{
if(Tree)
{
printf("%c",Tree->value);
PreOrder(Tree->LChild);
PreOrder(Tree->RChild);
}
}

//递归中序遍历二叉树
void MidOrder(BiTree Tree)
{
if(Tree)
{
MidOrder(Tree->LChild);
printf("%c",Tree->value);
MidOrder(Tree->RChild);
}
}

//递归后序遍历二叉树
void PostOrder(BiTree Tree)
{
if(Tree)
{
PostOrder(Tree->LChild);
PostOrder(Tree->RChild);
printf("%c",Tree->value);
}
}

//非递归前序遍历二叉树
void NPreOrder(BiTree Tree)
{
BiTNode *p;
S = InitLinkStack(S);
p = Tree;
while(p || count != 0)
{
if(p)
{
if(p->RChild)
Push(S,p->RChild);
printf("%c",p->value);
p = p->LChild;
}
else
p = Pop(S);
}
}

//非递归中序遍历二叉树
void NMidOrder(BiTree Tree)
{
//char ch;
BiTNode *p;
S = InitLinkStack(S);
p = Tree;
while(p || count != 0)
{
if(p)
{
Push(S,p);
p = p->LChild;
}
else
{
p = Pop(S);
printf("%c",p->value);
p = p->RChild;
}
}
}

//非递归后序遍历二叉树
void NPostOrder(BiTree Tree)
{
BiTNode *p,*q = NULL;
S = InitLinkStack(S);
p = Tree;
while(p || count != 0)
{
if(p)
{
Push(S,p);
p = p->LChild;
}
else
{
p = S->link->pointer;
if(p->RChild == NULL || p->RChild == q)
{
p = Pop(S);
printf("%c",p->value);
q = p;
p = NULL;
}
else
{
//p = Pop(S);
p = p->RChild;
}
}
}
}
//初始化链栈
LinkStackNode *InitLinkStack(LinkStack top)
{
top = (LinkStackNode *)malloc(sizeof(LinkStackNode));
return top;
}

//进栈操作
void Push(LinkStack top,BiTNode *p)
{
LinkStackNode *temp;
temp = (LinkStackNode *)malloc(sizeof(LinkStackNode));
if(temp)
{
temp->pointer = p;
temp->link = top->link;
top->link = temp;
count++;
}
}

//出栈操作
BiTNode * Pop(LinkStack top)
{
//char ch;
BiTNode *p;
LinkStackNode *temp;
p = (BiTNode *)malloc(sizeof(BiTNode));
temp = top->link;
if(temp)
{
top->link = temp->link;
p = temp->pointer;
free(temp);
count--;
}
return p;
}

简单啊 都给你，书上有原版的，链式存储的哦

typedef int TElemType;//定义
typedef struct BitNode
{ TElemType data;
struct BitNode *lchild,*rchild;
}BitNode,*BitTree;

void PreOrderTraverse(BitTree bt)//先序遍历
{ if(bt!=NULL)
{printf("%d",bt->data);
PreOrderTraverse(bt->lchild);
PreOrderTraverse(bt->rchild);
}

void InOrderTraverse(BitTree bt)//中序遍历
{ if(bt!=NULL)
{ InOrderTraverse(bt->lchild);
printf("%d",bt->data);
InOrderTraverse(bt->rchild);
}

void PostOrderTraverse(BitTree bt)//后序遍历
{ if(bt!=NULL)
{ PostOrderTraverse(bt->lchild);
PostOrderTraverse(bt->rchild);
printf("%d",bt->data);
}

三种啊。千序遍历DLR:先根结点，再左子树，后右子树
中序遍历LDR：先左子树，再根结点。后右子树
后序遍历LRD:先左子树，再右子树，后根结点

我有霍夫曼树的遍历，你要不？