int CountLeaf2(BiTree bt) {/*开始时,bt 为根结点所在链结点的指针,返回值为bt 的叶子数*/ if ( bt==NULL ) return ( 0 ); if ( bt->lchild==NULL && bt->rchild==NULL ) return ( 1 ); return ( CountLeaf2 ( bt->lchild ) +CountLeaf2 ( bt->rchild ) ); }