#include "stdio.h"
typedef char ElemType;
typedef struct BiTNode{
ElemType data;
struct BiTNode *lchild,*rchild;
}BiTNode;
void preorder(BiTNode *bt)
{ if(bt!=NULL)
{ printf("%c ",bt->data);
preorder(bt->lchild);
preorder(bt->rchild);
}
}
void inorder(BiTNode *bt)
{ inorder(bt->lchild);
printf("%c ",bt->data);
inorder(bt->rchild);
void postorder(BiTNode *bt)
{ postorder(bt->lchild);
postorder(bt->rchild);
void preorder_fdg(BiTNode *bt)
{ int i=0;
BiTNode *p,*s[20];
p=bt;
do
{ while(p!=NULL)
{ s[i++]=p;
p=p->lchild;
}
if(i>0)
{ p=s[--i];
printf("%c ",p->data);
p=p->rchild;
}while(i>0||p!=NULL);
void inorder_fdg(BiTNode *bt)
void postorder_fdg(BiTNode *bt)
{ int i=0,b,s2[20];
{ s[i]=p;
s2[i++]=0;
if(i>=0) {
b=s2[--i];
p=s[i];
if (b==0)
{s[i]=p;
s2[i++]=1;
}
else
{printf("%c ",p->data); p=NULL;}
}while(i>0);
void lev_traverse(BiTNode* T)
{
BiTNode *q[100],*p;
int head,tail, i;
q[0]=T;head=0;tail=1;
while(head<tail) {
p=q[head++];
printf("%c ",p->data);
if(p->lchild!=NULL)
q[tail++]=p->lchild;
if(p->rchild!=NULL)
q[tail++]=p->rchild;
}
BiTNode *crt_bt_pre()
{ char ch;
BiTNode *bt;
scanf("%c",&ch);
if(ch==' ') bt=NULL;
else
{if (ch!='#')
{ bt=(BiTNode *)malloc(sizeof(BiTNode));
bt->data=ch;
bt->lchild=crt_bt_pre();
bt->rchild=crt_bt_pre();
}
else
return(bt);}
return(bt);
void freetree(BiTNode *bt)
{ freetree(bt->lchild);
freetree(bt->rchild);
free(bt);
bt=NULL;
main()
BiTNode *T,*temp[20];
/*temp[0]=(BiTNode*)malloc(sizeof(BiTNode));
temp[0]->data = '-';
temp[1]=(BiTNode*)malloc(sizeof(BiTNode));
temp[1]->data = '+';
temp[0]->lchild = temp[1];
temp[2]=(BiTNode*)malloc(sizeof(BiTNode));
temp[2]->data = '/';
temp[0]->rchild = temp[2];
temp[3]=(BiTNode*)malloc(sizeof(BiTNode));
temp[3]->data = 'a';
temp[3]->lchild=NULL; temp[3]->rchild=NULL;
temp[1]->lchild = temp[3];
temp[4]=(BiTNode*)malloc(sizeof(BiTNode));
temp[4]->data = '*';
temp[1]->rchild = temp[4];
temp[5]=(BiTNode*)malloc(sizeof(BiTNode));
temp[5]->data = 'e';
temp[5]->lchild=NULL; temp[5]->rchild=NULL;
temp[2]->lchild = temp[5];
temp[6]=(BiTNode*)malloc(sizeof(BiTNode));
temp[6]->data = 'f';
temp[6]->lchild=NULL; temp[6]->rchild=NULL;
temp[2]->rchild = temp[6];
temp[7]=(BiTNode*)malloc(sizeof(BiTNode));
temp[7]->data = 'b';
temp[7]->lchild=NULL; temp[7]->rchild=NULL;
temp[4]->lchild = temp[7];
temp[8]=(BiTNode*)malloc(sizeof(BiTNode));
temp[8]->data = '-';
temp[4]->rchild = temp[8];
temp[9]=(BiTNode*)malloc(sizeof(BiTNode));
temp[9]->data = 'c';
temp[9]->lchild=NULL; temp[9]->rchild=NULL;
temp[8]->lchild = temp[9];
temp[10]=(BiTNode*)malloc(sizeof(BiTNode));
temp[10]->data = 'd';
temp[10]->lchild=NULL; temp[10]->rchild=NULL;
temp[8]->rchild = temp[10];*/
T=crt_bt_pre();
/* T=temp[0]; */
printf("\n\nPreOrder:\n");
preorder(T);
printf("\n\nInOrder:\n");
inorder(T);
printf("\n\nPostOrder:\n");
postorder(T);
printf("\n\ninorder_fdg:\n");
inorder_fdg(T);
printf("\n\nPostOrder:\n");;
postorder_fdg(T);
printf("\n\nlev_traverse:\n");
lev_traverse(T);