P-complete

Ordered High Degree Vertex Removal (OHDVR)

Category: Graph Theory

Input

An undirected graph $G = (V, E)$ with a numbering on the vertices in $V$, and two designated vertices $u$ and $v$.

Problem

Is there an elimination order on $V$, $v_1, \ldots, v_n$, satisfying the properties that $u$ is eliminated before $v$ and for $1 \leq i \leq n$, $v_i$ is the lowest numbered vertex of maximum degree in the $(i-1)$-st remaining subgraph of $G$?

Definitions

An elimination order is a sequence of vertices ordered as they and their corresponding edges are to be deleted from the graph.

Status

$\P$-complete (Greenlaw [1]).

Remarks

The reduction to show hardness is from NANDCVP.

References

  1. R. Greenlaw (1989). Ordered vertex removal and subgraph problems.
  2. Greenlaw, R., Hoover, H. J., and Ruzzo, W. L. (1995). Limits to Parallel Computation: P-Completeness Theory. Oxford University Press. Problem A.2.10.