指标1：minimum vertex-cut By a vertex-cut in a graph G,we mean a (strict) subset U of vertices of G such that G-U is disconnected. A vertex-cut of minimum cardinality in G is called a minimum vertex-cut指标1：minimum vertex-cut By a vertex-cut in a graph 𝐺 , we mean a (strict) subset 𝑈 of vertices of 𝐺 such that 𝐺 − 𝑈 is disconnected. 𝐴 vertex-cut of minimum cardinality in 𝐺 is called a minimum vertex-cut