he17 invalid output

[bslavchev]

Using the tdecomp driver and --he17, I get invalid decompositions on any/all graphs:

(base) ➜  examples git:(develop) ✗ ./tdecomp --he17 < gr/testgraph3.gr | grep -v incomplete > test.td
starting threads for 15 bit mode
(base) ➜  examples git:(develop) ✗ ./td-validate gr/testgraph3.gr test.td
terminate called after throwing an instance of 'exception_invalid_td'
  what():  Invalid s-line: Reported bagsize and actual bagsize differ
[1]    55789 IOT instruction (core dumped)  ./td-validate gr/testgraph3.gr test.td

The decomposition itself:

c status 166 1674055642465 initial
c n: 166, e: 194
c gala on

[felix-salfelder]

On Wed, Jan 18, 2023 at 07:31:06AM -0800, Bobby Slavchev wrote: Using the tdecomp driver and --he17, I get invalid decompositions on any/all graphs:

Thanks for the bug report. Digging into the code, it seems that he17 never made it into the tdecomp driver. It would have been the pace'17 heuristic, aka p17. If you #define USE_P17 in tdecomp.cc, it will not even compile, because some wrapper header, he17_thread.h, does not exist. The closest I found is [1]... I'm not sure what shape the algorithm is in, but it may be worth a look.

what(): Invalid s-line: Reported bagsize and actual bagsize differ [..] c status 166 1674055642465 initial c n: 166, e: 194 c gala on

Looks like broken error handling in td-validate. Note that the input is essentially empty ('c' means "comment"). [1] https://github.com/freetdi/p17/blob/master/tdlib/grtd/p17.h