如何将有向无环图转换为树

Question

I want to convert a directed acyclic graph (DAG) into a tree, by duplicating the nodes that has more than one parent. what is the most efficient way of doing so?

Answer 1

You can use depth first search or breadth first search for that. Does not matter. The only difference is that you want duplicate the first vertices that you already visited (go into depth 1 of visited, not more).

Here is DFS for java: http://algs4.cs.princeton.edu/41graph/DepthFirstSearch.java.html , but there are many implementations.