输出二叉树的叶子

#include
#include
typedef char elemtype;
typedef struct node
{
	struct node *lchild;
	struct node *rchild;
	elemtype data;
} btnode;
void createbt(btnode *&b,char *str)
{
	btnode *p,*st[100];
	int j=0,k,top=-1;
	char ch;
	b=NULL;
	ch=str[j];
	while(ch!='\0')
	{
		switch(ch)
		{
			case '(':top++;st[top]=p;k=1;break;
			case ')':top--;break;
			case ',':k=2;break;
			default:
				p=(btnode *)malloc(sizeof(btnode));
				p->data=ch;
				p->lchild=p->rchild=NULL;
				if(b==NULL)
					b=p;
				else
				{
					switch(k)
					{
						case 1:st[top]->lchild=p;break;
						case 2:st[top]->rchild=p;break;
					}
				}
		}
		j++;ch=str[j];
	}
}
void displeaf(btnode *b)
{
	if(b!=NULL)
	{
		if(b->lchild==NULL&&b->rchild==NULL)
			printf("%c",b->data);
		displeaf(b->lchild);
		displeaf(b->rchild);
	}
}
int main()
{
	btnode *b;
	char str[50];
	printf("输入二叉树: ");
	scanf("%s",str);
	createbt(b,str);
	printf("叶子结点: ");
	displeaf(b);
	return 0;
}