
We study the computational complexity of graph planarization via edge contraction. The problem CONTRACT asks whether there exists a set $S$ of at most $k$ edges that when contracted produces a planar graph. We work with a more general problem called $P$-RESTRICTEDCONTRACT in which $S$, in addition, is required to satisfy a fixed MSOL formula $P(S,G)$. We give an FPT algorithm in time $O(n^2 f(k))$ which solves $P$-RESTRICTEDCONTRACT, where $P(S,G)$ is (i) inclusion-closed and (ii) inert contraction-closed (where inert edges are the edges non-incident to any inclusion minimal solution $S$). As a specific example, we can solve the $\ell$-subgraph contractibility problem in which the edges of a set $S$ are required to form disjoint connected subgraphs of size at most $\ell$. This problem can be solved in time $O(n^2 f'(k,\ell))$ using the general algorithm. We also show that for $\ell \ge 2$ the problem is NP-complete.
FOS: Computer and information sciences, Analysis of algorithms and problem complexity, Graph representations (geometric and intersection representations, etc.), planar graph, contraction, Planar graphs; geometric and topological aspects of graph theory, FPT algorithm, Graph algorithms (graph-theoretic aspects), Graph theory (including graph drawing) in computer science, MSOL formula, Computer Science - Data Structures and Algorithms, Data Structures and Algorithms (cs.DS)
FOS: Computer and information sciences, Analysis of algorithms and problem complexity, Graph representations (geometric and intersection representations, etc.), planar graph, contraction, Planar graphs; geometric and topological aspects of graph theory, FPT algorithm, Graph algorithms (graph-theoretic aspects), Graph theory (including graph drawing) in computer science, MSOL formula, Computer Science - Data Structures and Algorithms, Data Structures and Algorithms (cs.DS)
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 0 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
