AN O(|V|~2)ALGORITHM FOR THE PLANAR 4-CUT PROBLEM
平面图 4-割问题的 O(|V|~2)算法

A 4-cut for a connected graph G is a set of edges which,When deleted,separate G into 4components.In this paper an O(|V|~2) algorithm for finding the minimum 4-cut for a planargraph G is presented.