In this paper, we study the minimum-weight feedback vertex set problem in outerplanar graphs and present a linear time algorithm to solve it. 本文主要考虑外平面图中的反馈点集并给出了一个求外平面图最小顶点赋权反馈点集的线性时间算法。
The third part is to proof theimpaction set is finite.Comparing Hamiltonian systems without impacts, we should use a technical codition. 相对于没有碰撞的哈密顿系统而言,我们为了证明碰撞点集是有限集而加入了一些技术性条件。