遍历二叉树————非递归后续遍历

#include<stdio.h>

#include<string.h>

#include<stdlib.h>

#define max 1000

typedefchar datatype;

typedefstruct Node

{

    datatype data;

    structNode *lchild;

    structNode *rchild;

}BiTNode, *BiTree;

 

typedefstruct

{

    BiTree da[1000];

    inttop;

}SeqStack;

 

typedefstruct

{

    BiTree da[max];

    intfront;

    intrear;

}SeqQueue;

 

SeqQueue *InitQueue()

{

    SeqQueue *q;

    q = (SeqQueue *)malloc(sizeof(SeqQueue));

    q->front = q->rear = max-1;

    returnq;

}

 

intIsEmpty(SeqQueue *q)

{

    if(q->front == q->rear)

    return1;

    else

    return0;

}

 

voidEnterQueue(SeqQueue *q,BiTree root)

{

    BiTree p;

    p = root;

    if((q->rear+1) % max == q->front) {

        return;

    }

    else{

        q -> rear = (q->rear+1) % max;

        q->da[q->rear] = p;

    }

}

 

voidout(SeqQueue *q, BiTree *root)

{

    if(q->front == q->rear)

    return;

    else{

        q->front = (q->front+1)%max;

        *root = q->da[q->front];

    }

}

 

voidcreat(BiTree *root)

{

    charch;

    ch = getchar();

    if(ch == '#') {

        *root = NULL;

    }

    else{

        *root = (BiTree)malloc(sizeof(BiTNode));

        (*root)->data = ch;

        creat(&(*root)->lchild);

        creat(&(*root)->rchild);

    }

}

 

voidcengci(BiTree root)

{

    SeqQueue *s;

    BiTree p;

    s=InitQueue();

    EnterQueue(s,root);

    while(!IsEmpty(s)) {

        out(s,&p);

        printf("%c",p->data);

        if(p->lchild != NULL)

        EnterQueue(s,p->lchild);

        if(p->rchild != NULL)

        EnterQueue(s,p->rchild);

    }

    printf("\n");

}

 

//BIAOJI

voidgetTop(SeqStack *s, BiTree *p)

{

    if(Empty(s))

    return;

    else

    *p = s->da[s->top];

}

voidpush(SeqStack *s, BiTree root)

{

    BiTree p;

    p = root;

    if(s->top == 999)

        return;

    else{

        s->top++;

        s->da[s->top]=p;

    }

}

SeqStack  *InitStack()

{

    SeqStack *s;

    s=(SeqStack *)malloc(sizeof(SeqStack));

    s->top = -1;

    returns;

}

intEmpty(SeqStack *s)

{

    if(s->top == -1)

    return1;

    else

    return0;

}

voidpop(SeqStack *s, BiTree *root)

{

    BiTree p;

    p = *root;

    if(Empty(s))

        return;

    else{

        *root = s-> da[s->top];

        s->top--;

    }

}

voidPostOrder(BiTree root)

{

    SeqStack *s;

    BiTree p,q;

    s=InitStack();

    p = root;

    q = NULL;

    while(p != NULL || !Empty(s)) {

        while(p != NULL) {

            push(s,p);

            p = p -> lchild;

        }

        if(!Empty(s)) {

            getTop(s,&p);

            if(p->rchild==NULL || p->rchild == q) {

                 pop(s,&p);

                 printf("%c",p->data);

                 q=p;

                 p=NULL;

            }

            else

                p = p -> rchild;

        }

    }

}

intmain()

{

    BiTree root;

    creat(&root);

 //   cengci(root);

    PostOrder(root);

    return0;

}