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	<updated>2026-06-09T23:07:14Z</updated>
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	<entry>
		<id>https://acawiki.org/index.php?title=Total_ordering_problem&amp;diff=4249</id>
		<title>Total ordering problem</title>
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		<updated>2010-10-04T18:18:47Z</updated>

		<summary type="html">&lt;p&gt;Jfinkels: added the total ordering problem&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{Summary&lt;br /&gt;
|title=Total Ordering Problem&lt;br /&gt;
|authors=J. Opatrný&lt;br /&gt;
|tags=complexity, np-complete, computational complexity&lt;br /&gt;
|summary=Proves the NP-completeness of the total ordering problem: given finite sets S and R, where R is a subset of S x S x S, does there exist a total ordering of the elements of S such that for all (x, y, z) in R, either x &amp;lt; y &amp;lt; z or z &amp;lt; y &amp;lt; x? The reduction is from the hypergraph 2-colorability problem with edges of size at most 3.&lt;br /&gt;
&lt;br /&gt;
This problem is in &amp;quot;Computers and Intractibility&amp;quot; by Garey and Johnson as problem MS1, the betweenness problem.&lt;br /&gt;
|journal=SIAM Journal on Computing&lt;br /&gt;
|pub_date=1979&lt;br /&gt;
|doi=10.1137/0208008&lt;br /&gt;
|subject=Computer Science&lt;br /&gt;
}}&lt;/div&gt;</summary>
		<author><name>Jfinkels</name></author>
		
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