#include<iostream.h> typedef char TElemtype; typedef struct Btree { TElemtype data; struct Btree *Lchild,*Rchild; }BTnode,*btree; void create_btree(btree &root) { int i,j; btree s,p[100]; cin>>i; while(i!=0) { s=new BTnode; cin>>s->data; s->Lchild=s->Rchild=NULL; p[i]=s; if(i==1) root=s; else { j=i/2; if(i%2==0) p[j]->Lchild=s; else p[j]->Rchild=s; } cin>>i; } } void create_btree2(btree &root,char str[]) { char ch; static int i=0; ch=str[i++]; if(ch=='.') { root=NULL; } else { root=new BTnode; root->data=ch; create_btree2(root->Lchild,str); create_btree2(root->Rchild,str); } } void preorder(btree root) { if(root) { cout<<root->data; preorder(root->Lchild); preorder(root->Rchild); } } void inorder(btree root) { if(root) { inorder(root->Lchild); cout<<root->data; inorder(root->Lchild); } } void postorder(btree root) { if(root) { postorder(root->Lchild); postorder(root->Lchild); cout<<root->data; } } void main() { btree root; //create_btree(root); char str[30]; cin>>str; create_btree2(root,str); preorder(root); }