如何复制二郎有向图？

Question

如何复制二郎有向图？文档中似乎没有副本函数。我必须手动构建副本吗？

我在用药剂编码。

Answer 1

复制整个有向图的最佳方法是将digraph_utils:subgraph/2与Vertices = digraph:vertices(Digraph)结合使用。

测试：

在Digraph中创建A->B图，将其复制到Digraph2，并通过只向Digraph2添加"C"顶点来检查它是否是不同的图。

1> Digraph = digraph:new().
{digraph,16400,20497,24594,true}
2> digraph:add_vertex(Digraph,"A").
"A"
3> digraph:add_vertex(Digraph,"B").
"B"
4> digraph:add_edge(Digraph,"A","B").
['$e'|0]
5> Digraph2 = digraph_utils:subgraph(Digraph, digraph:vertices(Digraph)). 
{digraph,28691,32788,36885,true}
6> digraph:add_vertex(Digraph2, "C").
"C"
7> digraph:vertices(Digraph).
["B","A"]
8> digraph:vertices(Digraph2).
["C","B","A"]