二叉の木の中の度が0、1、2の結点の個数なことを求めます.

void leaf(btree* T,int &count)//count       
{
	if(T == NULL) //       
		return;
	if(T->lchild == NULL&&T->rchild == NULL)//       ==       && 
		count++;
	leaf(T->rchild,count);//          
	leaf(T->lchild,count);
}

/*       1    */

void degree1(btree* T,int &count)
{
	if(T == NULL)
		return;
	if((T->lchild == NULL &&T->rchild != NULL)||(T->rchild == NULL &&T->lchild != NULL))
		count++;
	degree1(T->lchild,count);
	degree1(T->rchild,count); 
}
/*      2  */ 
void degree2(btree *T,int &count)
{
	if(T == NULL)
		return;
	if(T->lchild != NULL&&T->rchild != NULL)
		count++;
	degree2(T->lchild,count);
	degree2(T->rchild,count);
}