JGraphT：计算图的交点

Question

使用JGraphT ，是否可以计算两个Graph对象的交点 （差/增量）？

还有其他Java图形库可以帮助我解决问题吗？

Answer 1

在JUNG中，解决此问题的最直接方法是构建顶点和边集的交集（或您喜欢的任何其他集操作），然后从结果中构建另一个图：

（使用Guava Sets类）

Graph<V, E> newGraph = ...; // create the appropriate graph type
for (V v : Sets.intersection(g1.getVertices(), g2.getVertices()) {
  newGraph.addVertex(v);
}

for (E e : Sets.intersection(g1.getEdges(), g2.getEdges()) {
  // Assume that each each e connects the same set of vertices in both
  // g1 and g2.  Otherwise you need to check that as well.
  V v1 = g1.getEndpoints(e).getFirst();
  V v2 = g1.getEndpoints(e).getSecond();
  // This contains check is necessary because the default implementations
  // of addEdge() will add v1 and v2 if they are not already present in
  // the graph, which you don't want to do if they're not in the intersection.
  if (newGraph.containsVertex(v1) && newGraph.containsVertex(v2)) {
    newGraph.addEdge(e, v1, v2);
  }
}