#13289: Determine if a vertex is a cut vertex
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Reporter: dcoudert | Owner: jason, ncohen, rlm
Type: enhancement | Status: needs_review
Priority: major | Milestone: sage-5.3
Component: graph theory | Resolution:
Keywords: | Work issues:
Report Upstream: N/A | Reviewers:
Authors: David Coudert | Merged in:
Dependencies: | Stopgaps:
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Comment (by sluther):
Nice work!
1)
{{{
4034 if not u in self.vertices():
}}}
should be:
{{{
4034 if u not in self:
}}}
2) Any reason you're using self._directed instead of self.is_directed() \\
3)
{{{
while len(queue) > 0:
}}}
should be:
{{{
while queue:
}}}
4) There is a potential performance optimization. Currently you first
perform the full dfs and then check if all neighbors of v have been seen.
You could instead mark the neighbors as seen once you saw them and abort
the dfs once you saw all of them. \\
i.e. store them in a set and call discard on the set whenever you add a
vertex to 'seen'. Then abort the dfs when the set is empty.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13289#comment:15>
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