Clique decision problem (source code)

= Clique decision problem

Given an explicitly represented finite <simple graph> $G$ and a nonnegative <integer> $k$, decide whether $G$ contains a <clique> of size $k$. The problem is <NP-complete>. A <polynomial-time many-one reduction> from <SAT> first obtains <conjunctive normal form> by a <Tseitin transformation>, makes one <vertex> per <Boolean literal> occurrence, and joins noncontradictory occurrences from different <Boolean clauses>. A <clique> as large as the <Boolean clause> count is equivalent to a <satisfying assignment>.