LICENSE.markdown @ 884333cfb6fb
v1.3.2
Detect *all* cycles during topological sort
Previously the cycle detection was limited to detecting when we hit
a currently-being-visited node during a traversal. So something like this would
be correctly found:
A --> B --> C
^ |
| |
+-----+
We start at the root (A), go to B, then to C, then to B, and detect that we're
still working on B and signal the error.
But this doesn't find all cycles, because we *start* at the root nodes, and if
a cycle doesn't have any outcropping branches we'll never reach it at all. For
example:
A --> B
^ |
| |
+-----+
This graph has no roots, so we incorrectly ignore the cycle.
This patch fixes the problem by keeping a count of visited nodes and and making
sure it matches the digraph's size at the end.
Fixes https://github.com/sjl/cl-digraph/issues/4
| author |
Steve Losh <steve@stevelosh.com> |
| date |
Mon, 14 Dec 2020 20:13:51 -0500 |
| parents |
b1e67e3dd37f |
| children |
(none) |
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