Lexicographically First Maximal Subgraph for π (LFMS(π))
Input
An undirected graph $G = (V, E)$ with an ordering on $V$, a designated vertex $v$, and a polynomial time testable, nontrivial, hereditary property $\pi$.
Problem
Is $v$ in the lexicographically first maximal subgraph $H$ of $G$ that satisfies $\pi$?
Definitions
A property is nontrivial if there are infinitely many graphs that satisfy the property and at least one graph that does not. A property $\pi$ is hereditary on induced subgraphs if whenever $G$ satisfies $\pi$, so do all vertex induced subgraphs.
Status
$\P$-complete (Miyano [1][2]).
Remarks
The following are examples of properties that meet the criteria stated in the problem: bipartite, chordal, clique (LFMC), comparability graph, edge graph, forest, independent set (LFMIS), outerplanar, and planar. Not all problems involving a lexicographically first solution are $\P$-complete. For example, the Lexicographically First Topological Order Problem is complete for $\mathsf{NLOG}$ and the Lexicographic Low Degree Subgraph Membership Problem is $\NP$-complete. For additional remarks relating to this problem see [3, Chapter 7].
References
- S. Miyano (1988). Parallel complexity and P-complete problems.
- S. Miyano (1989). The lexicographically first maximal subgraph problems: P-completeness and NC algorithms.
- Greenlaw, R., Hoover, H. J., and Ruzzo, W. L. (1995). Limits to Parallel Computation: P-Completeness Theory. Oxford University Press. Problem A.2.16.