longbinlai / graphbase Goto Github PK

Now there is a need to implement two kinds of iterators for the graph, a.k.a BfsIterator and DfsIterator, both implements Iterator interface.

You need to implement the function next() in the iterator, and by calling next() iteratively, we can get the traversal order (BFS, or DFS) correspondingly.

Note that in terms of space efficient, you may not maintain the bfs (and dfs) traversal results in advance. In addition, the graph may not be necessarily connected.

As we are moving to Java8, we should start programming with new Java 8 features. For example, we have the nice lambda function, which can purify your code a lot.

For example, if we have a Collection integers, and we want to print everything out, we can simply do:

integers.foreach(e -> {System.out.println(e);});

Can we re-implement the codes of remove (edges, vertices) etc. wherever you iterate the graph to do some operation to this kind of lambda function?