@@ -0,0 +1,244 @@
+package org.psjava.ds.graph;%0D%0A%0D%0A%0D%0Apublic class OppositeInUndirectedEdge %7B%0D%0A%0D%0A%09public static %3CV, E extends UndirectedEdge%3CV%3E%3E V get(E e, V v) %7B%0D%0A%09%09return v.equals(e.v1()) ? e.v2() : e.v1();%0D%0A%09%7D%0D%0A%0D%0A%09private OppositeInUndirectedEdge() %7B%0D%0A%09%7D%0D%0A%0D%0A%7D%0D%0A

add a graph util - OppositeInUndirectedEdge