程序代码：

#include <stdio.h>
#include <malloc.h>
typedef struct tree{
    char data;
    struct tree *lchild,*rchild;
} tnode ,*ttree;
void create(ttree t){
    char ch;
    scanf(" s",&ch);
    if(ch=='#')
        t=NULL;
    else{
        t=(ttree)malloc(sizeof(tnode));
        t->data=ch;
        create(t->lchild);
        create(t->rchild);
    }
}
void main(){
    ttree t;
    create(&t);
}