#include 
     
      #include 
      
       #include 
       
        using namespace std;typedef struct node{    char data;    struct node *lchild;    struct node *rchild;}Node;void buildTree(Node *&node){    char data;    scanf("%c",&data);    if(data=='#')   //如果输入的是'#'，则该节点为NULL    {        node=NULL;        return;    }    else    {        node=new Node;        node->data=data;        buildTree(node->lchild);  //递归地构建左子树        buildTree(node->rchild);  //递归地构建右子树        return;    }}void preOrder(Node *root){    if(root)    {        cout<
        
         data;        preOrder(root->lchild);        preOrder(root->rchild);    }}int main(){    Node *root;    buildTree(root);    //样例输入：124##5##3##    preOrder(root);     //前序遍历输出：12453    return 0;}