非递归遍历二叉树

来源：互联网发布：淘宝多肉种子哪家好编辑：程序博客网时间：2024/06/04 18:55
#include<iostream>#include<stdlib.h>#include<stdio.h>using namespace std;#define OK 1#define ERROR 0#define OVERFLOW 0#define TRUE 1#define FALSE 0typedef char TElemType;typedef struct BiTNode{    TElemType data;    struct BiTNode *lchild,*rchild;} BiTNode,*BiTree;typedef BiTree sElemType;typedef int Status;typedef struct StackNode{    sElemType data;    struct StackNode *next;} StackNode,*LinkStackPtr;typedef struct LinkStack{    LinkStackPtr top;    int sum;} LinkStack;//栈空Status StackEmpty(LinkStack *S){    if(S->sum == 0)    {        return TRUE;    }    else    {        return FALSE;    }}//入栈Status Push(LinkStack *S,sElemType e){    LinkStackPtr ls = (LinkStackPtr)malloc(sizeof(StackNode));    ls->data = e;    ls->next = S->top;    S->top = ls;    S->sum++;    return OK;}//出栈Status Pop(LinkStack *S,sElemType &e){    if(StackEmpty(S))    {        cout<<"栈空"<<endl;        return ERROR;    }    LinkStackPtr p = S->top;    S->top = p->next;    e = p->data;    free(p);    S->sum--;    return OK;}//获取栈顶元素Status GetTop(LinkStack *S,sElemType &e){    if(StackEmpty(S))    {        cout<<"栈空"<<endl;        return ERROR;    }    LinkStackPtr p = S->top;    e = p->data;    free(p);    return OK;}Status init_BiTree(BiTree &T){    T = (BiTree)malloc(sizeof(BiTNode));    if(!T)    {        exit(OVERFLOW);    }    return OK;}Status CreateBiTree(BiTree &T){    BiTree b = (BiTree)malloc(sizeof(BiTNode));    char ch = cin.get();    if(ch == ' ')    {        cout<<"NUll"<<endl;        T = NULL;    }    else    {        cout<<"再次输入-------------"<<endl;        if(!(T=(BiTree)malloc(sizeof(BiTNode))))        {            exit(OVERFLOW);        }        T ->data = ch;        CreateBiTree(T->lchild);        CreateBiTree(T->rchild);    }    return OK;}//中序遍历 循环：（向左走到尽头，弹出空结点后，取栈顶元素数据，然后将其右孩子压入栈）Status InOrderTraverse (BiTree T,Status (*Visit)(TElemType e)){    LinkStack *S ;    S=(LinkStack*)malloc(sizeof(LinkStack));    S->sum=0;    Push(S,T);    BiTree p;    while(!StackEmpty(S))    {        while(GetTop(S,p)&&p)        {            Push(S,p->lchild);//向左走到尽头        }        Pop(S,p);        if(!StackEmpty(S))        {            Pop(S,p);            if(!Visit(p->data))            {                return ERROR;            }            Push(S,p->rchild);        }    }    return OK;}//前序遍历Status PreOrderTraverse (BiTree T,Status (*Visit)(TElemType e)){    LinkStack *S ;    //InitStack(S);    S=(LinkStack*)malloc(sizeof(LinkStack));    S->sum=0;    Push(S,T);    BiTree p;    while(!StackEmpty(S))    {        while(GetTop(S,p)&&p)        {            if(!Visit(p->data))            {                return ERROR;            }            Push(S,p->lchild);//向左走到尽头        }        Pop(S,p);//弹出空结点        if(!StackEmpty(S))        {            Pop(S,p);//弹出左兄弟结点            Pop(S,p);//弹出双亲            Push(S,p->rchild);//右兄弟结点压入栈中        }    }    return OK;}//后续遍历Status PostOrderTraverse(BiTree T,Status(*Visit)(TElemType e)){    LinkStack *S;    S = (LinkStack*)malloc(sizeof(LinkStack));    S->sum = 0;    BiTree p;//当前结点    BiTree pLastVisit;//记录上次访问的结点    Push(S,T);    while(GetTop(S,p)&&p)    {        Push(S,p->lchild);//向左走到尽头    }    Pop(S,p);//弹出空结点    while(!StackEmpty(S))    {        Pop(S,p);        if(p)        {            //如果没有右子树或右子树已经访问过（输出结点包含的数值），再访问该结点数            if(p->rchild == NULL||p->rchild==pLastVisit)            {                if(!Visit(p->data))                {                    return ERROR;                }                pLastVisit = p;            }            //如果有右子树且没有访问过，右结点入栈，同时向左走到尽头            else            {                Push(S,p);                p = p->rchild;                while(p)                {                    Push(S,p);                    p = p->lchild;                }            }        }    }}Status Visit(TElemType e){    if(e ==NULL)    {        return ERROR;    }    cout<<e<<"--";    return OK;}int main(){    BiTree T;    CreateBiTree(T);    cout<<"输入完毕"<<endl;    PostOrderTraverse(T,Visit);}
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