Recognizing when heuristics can approximate minimum vertex covers is complete for parallel access to NP

Hemaspaandra, Edith; Rothe, Jörg; Spakowski, Holger

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Tome 40 (2006) no. 1, pp. 75-91.

For both the edge deletion heuristic and the maximum-degree greedy heuristic, we study the problem of recognizing those graphs for which that heuristic can approximate the size of a minimum vertex cover within a constant factor of $r$, where $r$ is a fixed rational number. Our main results are that these problems are complete for the class of problems solvable via parallel access to $\text{NP}$. To achieve these main results, we also show that the restriction of the vertex cover problem to those graphs for which either of these heuristics can find an optimal solution remains NP-hard.

Classification : 68Q15, 68Q17
Mots clés : computational complexity, completeness, minimum vertex cover heuristics, approximation, parallel access to NP

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