#include <stdio.h>
#include <stdlib.h>

//定义二叉树
typedef char ElemType;
typedef struct BiTNode{
    ElemType data;
    struct BiTNode *lchild,*rchild;
}BTree;


//创建一棵二叉树
void CreateBT(BTree *bt){
    char ch;

    scanf("%c",&ch);
    if(ch=='#') bt=NULL;
    else{
        bt=(BTree *)malloc(sizeof(BTree));
        bt->data=ch;
        CreateBT(bt->lchild);
        CreateBT(bt->rchild);
    }

}
//先序遍历二叉树
void PreOrder(BTree *bt){
    if(bt!=NULL){
        printf("%c",bt->data);
        PreOrder(bt->lchild);
        PreOrder(bt->rchild);
    }
}
int main() {
    BTree *bt;
    //建立一棵二叉树
    printf("按前序序列输入一棵二叉树;\n");
    CreateBT(bt);

    //先序遍历二叉树
    printf("前序遍历二叉树:\n");
    PreOrder(bt);
    return 0;
}
编译过了，运行不了，求大神指点