#include <stdio.h>#include <stdlib.h>typedef struct tree{    int n;    struct tree *l;    struct tree *r;}tree;tree a[8];   int s=1;    void bl(tree* h);int main(){    int i;    tree *h1;    h1=&a[1];    for( i=1;i<4;i++)    {        a[i].l=&a[2*i];        a[i].r=&a[2*i+1];        a[i].n=i;    }    for(i=4;i<8;i++)    {        a[i].l=NULL;        a[i].r=NULL;        a[i].n=i;    }    bl(h1);    system("pause");    return 0;}void bl(tree *h){    tree*  l[20];    tree** p;    tree** pp;    tree *t=h;//頭節點標識    int m[20];    int *q;    int i;    q=&m[1];    p=&l[1];//printf("%d",m[19]);    for (i=0;i<20;i++){        l[i]=0;m[i]=0;}    *p=t;//頭節點標識    *q=1;      while(p!=&l[0]){       while(t!=NULL){           p++;//l位進1        q++;             (*q)=1;         (*p)=t->l;         t=t->l;                       }         p--;q--;         pp=p-1;             if(p!=&l[0]&&(*q)==1){        (*q)++;        p++;        q++;        (*p)=(*pp)->r;        t=(*p);                      }        if(p!=&l[0]&&*q==2){        printf("%d",(*p)->n);        *q=0;        t=NULL;    }   }   /**/}