4.3.1二叉树的遍历
 
function.h
 
#include <stdio.h>
#include <stdlib.h>
typedef char BiElemType;
typedef struct BiTNode{
	BiElemType c;
	struct BiTNode *lchild;
	struct BiTNode *rchild;
}BiTNode,*BiTree;
typedef struct tag{
	BiTree p;
	struct tag *pnext;
}tag_t,*ptag_t;
#define MaxSize 50
typedef BiTree ElemType;
typedef struct{
	ElemType data[MaxSize];
	int top;
}SqStack;
void InitStack(SqStack &S);
bool StackEmpty(SqStack &S);
bool Push(SqStack &S,ElemType x);
bool Pop(SqStack &S,ElemType &x);
bool GetTop(SqStack &S,ElemType &x);
typedef struct LinkNode{
	ElemType data;
	struct LinkNode *next;
}LinkNode;
typedef struct{
	LinkNode *front,*rear;
}LinkQueue;
void InitQueue(LinkQueue &Q);
bool IsEmpty(LinkQueue Q);
void EnQueue(LinkQueue &Q,ElemType x);
bool DeQueue(LinkQueue &Q,ElemType &x);
 
stack.cpp
 
#include "function.h"
void InitStack(SqStack &S)
{
	S.top=-1;
}
bool StackEmpty(SqStack &S)
{
	if(S.top==-1)
		return true;
	else
		return false;
}
bool Push(SqStack &S,ElemType x)
{
	if(S.top==MaxSize-1)
	{
		return false;
	}
	S.data[++S.top]=x;
	return true;
}
bool Pop(SqStack &S,ElemType &x)
{
	if(-1==S.top)
		return false;
	x=S.data[S.top--];
	return true;
}
bool GetTop(SqStack &S,ElemType &x)
{
	if(-1==S.top)
		return false;
	x=S.data[S.top];
	return true;
}
 
queue.cpp
 
#include "function.h"
void InitQueue(LinkQueue &Q)
{
	Q.front=Q.rear=(LinkNode*)malloc(sizeof(LinkNode));
	Q.front->next=NULL;
}
bool IsEmpty(LinkQueue Q)
{
	if(Q.front==Q.rear)
		return true;
	else
		return false;
}
void EnQueue(LinkQueue &Q,ElemType x)
{
	LinkNode *s=(LinkNode *)malloc(sizeof(LinkNode));
	s->data=x;s->next=NULL;
	Q.rear->next=s;
	Q.rear=s;
}
bool DeQueue(LinkQueue &Q,ElemType &x)
{
	if(Q.front==Q.rear) return false;
	LinkNode *p=Q.front->next;
	x=p->data;
	Q.front->next=p->next;
	if(Q.rear==p)
		Q.rear=Q.front;
	free(p);
	return true;
}
 
main.cpp
 
#include "function.h"
void preOrder(BiTree p)
{
	if(p!=NULL)
	{
		putchar(p->c);
		preOrder(p->lchild);
		preOrder(p->rchild);
	}
}
void InOrder(BiTree p)
{
	if(p!=NULL)
	{
		InOrder(p->lchild);
		putchar(p->c);
		InOrder(p->rchild);
	}
}
void PostOrder(BiTree p)
{
	if(p!=NULL)
	{
		PostOrder(p->lchild);
		PostOrder(p->rchild);
		putchar(p->c);
	}
}
void InOrder2(BiTree T)
{
	SqStack S;
	InitStack(S);BiTree p=T;
	while(p||!StackEmpty(S))
	{
		if(p)
		{
			Push(S,p);
			p=p->lchild;
		}else{
			Pop(S,p);putchar(p->c);
			p=p->rchild;
		}
	}
}
void LevelOrder(BiTree T)
{
	LinkQueue Q;
	InitQueue(Q);
	BiTree p;
	EnQueue(Q,T);
	while(!IsEmpty(Q))
	{
		DeQueue(Q,p);
		putchar(p->c);
		if(p->lchild!=NULL)
			EnQueue(Q,p->lchild);
		if(p->rchild!=NULL)
			EnQueue(Q,p->rchild);
	}
}
int main()
{
	BiTree pnew;
	int i,j,pos;
	char c;
	BiTree tree=NULL;
	ptag_t phead=NULL,ptail=NULL,listpnew,pcur;
	
	while(scanf("%c",&c)!=EOF)
	{
		if(c=='\n')
		{
			break;
		}
		pnew=(BiTree)calloc(1,sizeof(BiTNode));
		pnew->c=c;
		listpnew=(ptag_t)calloc(1,sizeof(tag_t));
		listpnew->p=pnew;
		if(NULL==tree)
		{
			tree=pnew;
			phead=listpnew;
			ptail=listpnew;
			pcur=listpnew;
			continue;
		}else{
			ptail->pnext=listpnew;
			ptail=listpnew;
		}
		if(NULL==pcur->p->lchild)
		{
			pcur->p->lchild=pnew;
		}else if(NULL==pcur->p->rchild)
		{
			pcur->p->rchild=pnew;
			pcur=pcur->pnext;
		}
	}
	printf("--------前序遍历----------\n");
	preOrder(tree);
	printf("\n--------中序遍历------------\n");
	InOrder(tree);
	printf("\n--------后序遍历------------\n");
	PostOrder(tree);
	printf("\n--------中序遍历非递归------\n");
	InOrder2(tree); 
	printf("\n--------层次遍历-----------\n");
	LevelOrder(tree);
	printf("\n");
	system("pause");
} 
 
4.3.2线索二叉树
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef char ElemType;
typedef struct ThreadNode{
	ElemType data;
	struct ThreadNode *lchild,*rchild;
	int ltag,rtag;
}ThreadNode,*ThreadTree;
void BulidThreadTree(ThreadTree &T)
{
	ThreadTree arr[5];
	int i;
	for(i=0;i<5;i++)
	{
		arr[i]=(ThreadTree)malloc(sizeof(ThreadNode));
		memset(arr[i],0,sizeof(ThreadNode));
		arr[i]->data='A'+i;
	}
	arr[0]->lchild=arr[1];
	arr[0]->rchild=arr[2];
	arr[1]->rchild=arr[3];
	arr[2]->lchild=arr[4];
	T=arr[0];
}
void InThread(ThreadTree &p,ThreadTree &pre)
{
	if(p!=NULL){
		InThread(p->lchild,pre);
		if(p->lchild==NULL){
			p->lchild=pre;
			p->ltag=1;
		}
		if(pre!=NULL&&pre->rchild==NULL){
			
			pre->rchild=p;
			pre->rtag=1;
		}
		pre=p;
		InThread(p->rchild,pre);
	}
}
void CreateInThread(ThreadTree T)
{
	ThreadTree pre=NULL;
	if(T!=NULL){
		InThread(T,pre);
		pre->rchild=NULL;
		pre->rtag=1;
	}
}
ThreadNode *Firstnode(ThreadNode *p)
{
	while(p->ltag==0)
		p=p->lchild;
	return p;
}
int main()
{
	ThreadTree T;
	ThreadTree p;
	BulidThreadTree(T);
	CreateInThread(T);
	p=Firstnode(T);
	printf("最左下结点值为 %c\n",p->data);
	system("pause");
}
 
4.5二叉排序列
 
#include <stdio.h>
#include <stdlib.h>
typedef int KeyType;
typedef struct BSTNode{
	KeyType key;
	struct BSTNode *lchild,*rchild;
}BSTNode,*BiTree;
int BST_Insert(BiTree &T,KeyType k)
{
	if(NULL==T)
	{	
		T=(BiTree)malloc(sizeof(BSTNode));
		T->key=k;
		T->lchild=T->rchild=NULL;
		return 1;
	}
	else if(k==T->key)
		return 0;
	else if(k<T->key)
		return BST_Insert(T->lchild,k);
	else
		return BST_Insert(T->rchild,k);
}
void Creat_BST(BiTree &T,KeyType str[],int n)
{
	T=NULL;
	int i=0;
	while(i<n)
	{
		BST_Insert(T,str[i]);
		i++;
	}
}
BSTNode *BST_Search(BiTree T,KeyType key,BiTree &p)
{
	p=NULL;
	while(T!=NULL&&key!=T->key)
	{
		p=T;
		if(key<T->key) T=T->lchild;
		else T=T->rchild;
	}
	return T;
}
void DeleteNode(BiTree &root,KeyType x){
    if(root == NULL){
        return;
    }
    if(root->key>x){
        DeleteNode(root->lchild,x);
    }else if(root->key<x){
        DeleteNode(root->rchild,x);
    }else{ 
        if(root->lchild == NULL){ 
           BiTree tempNode = root;
           root = root->rchild;
           free(tempNode);
        }else if(root->rchild == NULL){ 
           BiTree tempNode = root;
           root = root->lchild;
           free(tempNode);
        }else{  
            
            BiTree tempNode = root->lchild;
            if(tempNode->rchild!=NULL){
                tempNode = tempNode->rchild;
            }
            root->key = tempNode->key;
            DeleteNode(root->lchild,tempNode->key);
        }
    }
}
void InOrder(BiTree T)
{
	if(T!=NULL)
	{
		InOrder(T->lchild);
		printf("%3d",T->key);
		InOrder(T->rchild);
	}
}
int main()
{
	BiTree T;
	BiTree parent;
	BiTree search;
	KeyType str[]={54,20,66,40,28,79,58};
	Creat_BST(T,str,7);
	InOrder(T);
	printf("\n");
	search=BST_Search(T,40,parent);
	if(search)
	{
		printf("找到对应结点,值=%d\n",search->key);
	}else{
		printf("未找到对应结点\n");
	}
	DeleteNode(T,66);
	InOrder(T);
	printf("\n");
	system("pause");
}