请高手指点，为什么我这个树不能建立
#include<stdio.h>#include<stdlib.h>
typedef struct bintree
{
int data;
struct bintree *lchild;
struct bintree *rchild;
}tnode;
int creattree(tnode* &t)
{ int ch;
scanf("%d",&ch);
if(ch=='0') t=NULL;
else
{ if(!(t=(tnode*)malloc(sizeof(tnode))))
return 0;
t->data=ch;
creattree(t->lchild);
creattree(t->rchild);
}
}
int main()
{
tnode * bt;
creattree(bt);
printf("%d",bt->data);
system("pause");
}
