二叉樹後序遍歷的非遞歸算法

 #include<stdio.h>
#include <stdlib.h>
#define maxsize 50
typedef struct Bnode //聲明二叉樹的數據結構
{
char data;
struct Bnode *lchild,*rchild;
}bnode,*btree;
typedef struct type
{
btree node;
int flag;
}datatype,*pdatatype;
typedef struct{ //聲明棧的數據結構
datatype data[maxsize];//pdatatype data[maxsize]; //類型改爲datatype
int top;
}seqstack,*pseqstack;
int i=0;
btree creatbtree(char *s) //創建二叉樹
{
btree t;
if(s[i]=='#')
{t=NULL;i++;}
else
{
t=(btree)malloc(sizeof(bnode));
t->data=s[i];i++;
t->lchild=creatbtree(s);
t->rchild=creatbtree(s);
}
return t;
}
void postorder(btree t) //二叉樹的後序遍歷(非遞歸)
{
int cout;
pseqstack p;
//pdatatype sq;
//sq=(pdatatype)malloc(sizeof(datatype));
p=(pseqstack)malloc(sizeof(seqstack));
p->top=0;
while(t||!(p->top==0))
{
if(t)
{
//sq->flag=0;
//sq->node=t;
//p->data[p->top]=sq;
p->data[p->top].node = t;
p->data[p->top].flag = 0;
(p->top)++;
t=t->lchild;
}
else
{ 
//sq=p->data[(p->top)-1];
//t=sq->node;
if(p->data[p->top-1].flag==0)
{ 
p->data[p->top-1].flag=1;
//sq->node=t;
//p->data[p->top]=sq;
//(p->top)++;
t = p->data[p->top-1].node->rchild;//t=t->rchild;
}
else
{
printf("%c",p->data[p->top-1].node->data); //printf("%c",t->data);
    (p->top)--;

//printf("%c",t->data);
//t=NULL;

}
}
}
}




main()
{
btree t;
char *s;
s="abd#g###ce##fh###";
t=creatbtree(s);
printf("/n後序遍歷：");
postorder(t);


}