Graphclass: matroidal

Definition:

A set F of edges of G = (V,E) is threshold independent if G[F] is a threshold graph. Let I_E denote the family of threshold independent edge sets. Then G is matroidal if (E,I_E ) is a matroid.

References

[866]

U.N. Peled
Matroidal graphs
Discrete Math. 20 1977 263--286

[1058]

R.I. Tyshkevich, A.A. Chernyak, Zh. A. Chernyak
Graphs and degree sequences II
Cybernetics (the English translation of Kibernetika) 24 1988 137--152

;

Equivalent classes

Only references for direct inclusions are given. Where no reference is given for an equivalent class, check other equivalent classes or use the Java application.

(C₅,K₂ ∪ K₃,K_2,3,P,P₂ ∪ P₃,P₅,P,P₂ ∪ P₃,co-fork,fork,house)-free
[866]
U.N. Peled
Matroidal graphs
Discrete Math. 20 1977 263--286
C₅-free ∩ matrogenic
[866]
U.N. Peled
Matroidal graphs
Discrete Math. 20 1977 263--286

Complement classes

self-complementary

Inclusions

The map shows the inclusions between the current class and a fixed set of landmark classes. Minimal/maximal is with respect to the contents of ISGCI. Only references for direct inclusions are given. Where no reference is given, check equivalent classes or use the Java application. To check relations other than inclusion (e.g. disjointness) use the Java application, as well.

Map

Inclusion map for matroidal

Minimal superclasses

(5,1) (known proper)
(C₅,P,P₅,P,co-fork,fork,house)-free (known proper)
(C₅,P₂ ∪ P₃,house)-free (known proper)
(C₅,P₅,P₂ ∪ P₃)-free (known proper)
(K₂ ∪ K₃,P,anti-hole)-free (known proper)
(K_2,3,P,hole)-free (known proper)
P₄-sparse (known proper)
XC₉-free (known proper)
chordal ∪ co-chordal
[866]
U.N. Peled
Matroidal graphs
Discrete Math. 20 1977 263--286

(known proper)
matrogenic [by definition] (known proper)

Maximal subclasses

(2K₂,C₄,C₅,claw,diamond)-free (known proper)
(2K₂,C₄,C₅,co-claw,co-diamond)-free (known proper)
(2K₂,C₄,P₄)-free (known proper)
(3K₁,P₃)-free (known proper)
Dilworth 1 (known proper)
(P₃,triangle)-free (known proper)
co-interval ∩ cograph ∩ interval (known proper)
co-trivially perfect ∩ trivially perfect (known proper)
cograph ∩ split (known proper)
comparability graphs of threshold orders (known proper)
linear NLC-width 1 (known proper)
maximum degree 1 (known proper)
threshold
[866]
U.N. Peled
Matroidal graphs
Discrete Math. 20 1977 263--286

(known proper)

Speed

[?]

The speed of a class $X$ is the function $n \mapsto |X_n|,ドル where $X_n$ is the set of $n$-vertex labeled graphs in $X$.

Depending on the rate of growths of the speed of the class, ISGCI distinguishes the following values of the parameter:
Constant
Polynomial
Exponential
Factorial
Superfactorial (2ドル^{o(n^2)}$ )
Superfactorial (2ドル^{\Theta(n^2)}$ )

factorial

at most factorial From bounded cliquewidth, maximum degree or degeneracy.
at least factorial on (2K₂,C₄,P₄)-free

[1785]

V.E. Alekseev
On lower layers of a lattice of hereditary classes of graphs
Diskretn. Anal. Issled. Oper. Ser. 1 4:1 3-12 (1997)

[1786]

E.R. Scheinerman, J. Zito
On the size of hereditary classes of graphs
J. Combin. Th. B Vol. 61 No.1 16-39 (1994)

[1787]

J. Balogh, B. Bollobas, D. Weinreich
The speed of hereditary properties of graphs
J. Combin. Th. B Vol. 79 No.2 131-156 (2000)

Parameters

acyclic chromatic number

[?]

The acyclic chromatic number of a graph $G$ is the smallest size of a vertex partition $\{V_1,\dots,V_l\}$ such that each $V_i$ is an independent set and for all $i,j$ that graph $G[V_i\cup V_j]$ does not contain a cycle.

Unbounded

Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from maximum clique

bandwidth

[?]

The bandwidth of a graph $G$ is the shortest maximum "length" of an edge over all one dimensional layouts of $G$. Formally, bandwidth is defined as $\min_{i \colon V \rightarrow \mathbb{N}\;}\{\max_{\{u,v\}\in E\;} \{|i(u)-i(v)|\}\mid i\text{ is injective}\}$.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from book thickness
Unbounded from branchwidth
Unbounded from carvingwidth
Unbounded from chromatic number
Unbounded from cutwidth
Unbounded from degeneracy
Unbounded from maximum clique
Unbounded from maximum degree
Unbounded from pathwidth
Unbounded from treewidth

Unbounded on complete [by definition]

book thickness

[?]

A book embedding of a graph $G$ is an embedding of $G$ on a collection of half-planes (called pages) having the same line (called spine) as their boundary, such that the vertices all lie on the spine and there are no crossing edges. The book thickness of a graph $G$ is the smallest number of pages over all book embeddings of $G$.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from maximum clique

Unbounded on complete

[1778]

F. Bernhart, P.C. Kainen
The book thickness of a graph
J. of Combin. Th. (B) 27 320-331 (1979)

booleanwidth

[?]

Consider the following decomposition of a graph $G$ which is defined as a pair $(T,L)$ where $T$ is a binary tree and $L$ is a bijection from $V(G)$ to the leaves of the tree $T$. The function $\text{cut-bool} \colon 2^{V(G)} \rightarrow R$ is defined as $\text{cut-bool}(A)$ := $\log_2|\{S \subseteq V(G) \backslash A \mid \exists X \subseteq A \colon S = (V(G) \backslash A) \cap \bigcup_{x \in X} N(x)\}|$. Every edge $e$ in $T$ partitions the vertices $V(G)$ into $\{A_e,\overline{A_e}\}$ according to the leaves of the two connected components of $T - e$. The booleanwidth of the above decomposition $(T,L)$ is $\max_{e \in E(T)\;} \{ \text{cut-bool}(A_e)\}$. The booleanwidth of a graph $G$ is the minimum booleanwidth of a decomposition of $G$ as above.

Bounded

Bounded from booleanwidth on the complement
Bounded from cliquewidth
Bounded from rankwidth

branchwidth

[?]

A branch decomposition of a graph $G$ is a pair $(T,\chi),ドル where $T$ is a binary tree and $\chi$ is a bijection, mapping leaves of $T$ to edges of $G$. Any edge $\{u, v\}$ of the tree divides the tree into two components and divides the set of edges of $G$ into two parts $X, E \backslash X,ドル consisting of edges mapped to the leaves of each component. The width of the edge $\{u,v\}$ is the number of vertices of $G$ that is incident both with an edge in $X$ and with an edge in $E \backslash X$. The width of the decomposition $(T,\chi)$ is the maximum width of its edges. The branchwidth of the graph $G$ is the minimum width over all branch-decompositions of $G$.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from book thickness
Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from maximum clique
Unbounded from treewidth

carvingwidth

[?]

Consider a decomposition $(T,\chi)$ of a graph $G$ where $T$ is a binary tree with $|V(G)|$ leaves and $\chi$ is a bijection mapping the leaves of $T$ to the vertices of $G$. Every edge $e \in E(T)$ of the tree $T$ partitions the vertices of the graph $G$ into two parts $V_e$ and $V \backslash V_e$ according to the leaves of the two connected components in $T - e$. The width of an edge $e$ of the tree is the number of edges of a graph $G$ that have exactly one endpoint in $V_e$ and another endpoint in $V \backslash V_e$. The width of the decomposition $(T,\chi)$ is the largest width over all edges of the tree $T$. The carvingwidth of a graph is the minimum width over all decompositions as above.

Unbounded

chromatic number

[?]

The chromatic number of a graph is the minimum number of colours needed to label all its vertices in such a way that no two vertices with the same color are adjacent.

Unbounded

Unbounded from maximum clique

cliquewidth

[?]

The cliquewidth of a graph is the number of different labels that is needed to construct the graph using the following operations:

creation of a vertex with label $i,ドル
disjoint union,
renaming labels $i$ to label $j,ドル and
connecting all vertices with label $i$ to all vertices with label $j$.

Bounded

Bounded from booleanwidth
Bounded from cliquewidth on the complement
Bounded from rankwidth

Bounded on (5,1)

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Bounded on (7,3)

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Bounded on (9,6)

[488]

A. Gy\'arf\'as, D. Kratsch, J. Lehel, F. Maffray
Minimal non--neighbourhood--perfect graphs
J. Graph Theory 21 55--66 1996

Bounded on (P,P,co-fork,fork)-free

[1185]

A. Brandstaedt, F.F. Dragan, H.-O. Le, R. Mosca
New graph classes of bounded clique-width
WG 2002, Lecture Notes in Computer Science 2573, 57-67 (2002)

Bounded on P₄-tidy

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Bounded on (P₅,fork,house)-free

[1185]

A. Brandstaedt, F.F. Dragan, H.-O. Le, R. Mosca
New graph classes of bounded clique-width
WG 2002, Lecture Notes in Computer Science 2573, 57-67 (2002)

[402]

J.L. Fouquet, V. Giakoumakis
On semi--$P_4$--sparse graphs
Discrete Math. 165/166 1997 277--300

Bounded on (P,fork,house)-free

[1185]

A. Brandstaedt, F.F. Dragan, H.-O. Le, R. Mosca
New graph classes of bounded clique-width
WG 2002, Lecture Notes in Computer Science 2573, 57-67 (2002)

[1186]

A. Brandstaedt, R. Mosca
On variations of P_4-sparse graphs.
Manuscript 2001

Bounded on cliquewidth 4
Bounded on partner-limited

[1179]

J.M. Vanherpe
Clique-width of partner-limited graphs.
International Conference of Graph Theory, Marseille 2000

Bounded on probe P₄-sparse
Bounded on (q, q-3), fixed q>= 7

[1176]

J.A. Makowsky, U. Rotics
On the clique-width of graphs with few $P_4$'s.
International Journal of Foundations of Computer Science 10 (1999) 329-348

Bounded on (q,q-4), fixed q

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Bounded on semi-P₄-sparse

[1186]

A. Brandstaedt, R. Mosca
On variations of P_4-sparse graphs.
Manuscript 2001

cochromatic number

[?]

The cochromatic number of a graph $G$ is the minimum number of colours needed to label all its vertices in such a way that that every set of vertices with the same colour is either independent in G, or independent in $\overline{G}$.

Unknown to ISGCI

cutwidth

[?]

The cutwidth of a graph $G$ is the smallest integer $k$ such that the vertices of $G$ can be arranged in a linear layout $v_1, \ldots, v_n$ in such a way that for every $i = 1, \ldots,n - 1,ドル there are at most $k$ edges with one endpoint in $\{v_1, \ldots, v_i\}$ and the other in $\{v_{i+1}, \ldots, v_n\}$.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from book thickness
Unbounded from branchwidth
Unbounded from carvingwidth
Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from maximum clique
Unbounded from maximum degree
Unbounded from pathwidth
Unbounded from treewidth

degeneracy

[?]

Let $G$ be a graph and consider the following algorithm:

Find a vertex $v$ with smallest degree.
Delete vertex $v$ and its incident edges.
Repeat as long as the graph is not empty.

The degeneracy of a graph $G$ is the maximum degree of a vertex when it is deleted in the above algorithm.

Unbounded

Unbounded from chromatic number
Unbounded from maximum clique

diameter

[?]

The diameter of a graph $G$ is the length of the longest shortest path between any two vertices in $G$.

Bounded

Bounded on P₇-free [by definition]

distance to block

[?]

The distance to block of a graph $G$ is the size of a smallest vertex subset whose deletion makes $G$ a block graph.

Unbounded

Unbounded on (3K₁,P₃)-free

[1827]

(no preview available)

Unbounded on complete split [trivial]

distance to clique

[?]

Let $G$ be a graph. Its distance to clique is the minimum number of vertices that have to be deleted from $G$ in order to obtain a clique.

Unbounded

Unbounded from distance to block
Unbounded from distance to cluster
Unbounded from distance to co-cluster
Unbounded from distance to cograph
Unbounded from maximum independent set
Unbounded from maximum induced matching
Unbounded from minimum clique cover
Unbounded from minimum dominating set

distance to cluster

[?]

A cluster is a disjoint union of cliques. The distance to cluster of a graph $G$ is the size of a smallest vertex subset whose deletion makes $G$ a cluster graph.

Unbounded

Unbounded from distance to block
Unbounded from distance to cograph

distance to co-cluster

[?]

The distance to co-cluster of a graph is the minimum number of vertices that have to be deleted to obtain a co-cluster graph.

Unbounded

Unbounded from distance to cluster on the complement
Unbounded from distance to cograph

distance to cograph

[?]

The distance to cograph of a graph $G$ is the minimum number of vertices that have to be deleted from $G$ in order to obtain a cograph .

Unbounded

Unbounded from distance to cograph on the complement

Unbounded on (2K₂,C₄,C₅,claw,diamond)-free

[1866]

(no preview available)

distance to linear forest

[?]

The distance to linear forest of a graph $G = (V, E)$ is the size of a smallest subset $S$ of vertices, such that $G[V \backslash S]$ is a disjoint union of paths and singleton vertices.

Unbounded

distance to outerplanar

[?]

The distance to outerplanar of a graph $G = (V,E)$ is the minumum size of a vertex subset $X \subseteq V,ドル such that $G[V \backslash X]$ is a outerplanar graph.

Unbounded

genus

[?]

The genus $g$ of a graph $G$ is the minimum number of handles over all surfaces on which $G$ can be embedded without edge crossings.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from book thickness
Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from maximum clique

max-leaf number

[?]

The max-leaf number of a graph $G$ is the maximum number of leaves in a spanning tree of $G$.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from bandwidth
Unbounded from book thickness
Unbounded from branchwidth
Unbounded from carvingwidth
Unbounded from chromatic number
Unbounded from cutwidth
Unbounded from degeneracy
Unbounded from distance to block
Unbounded from distance to linear forest
Unbounded from distance to outerplanar
Unbounded from maximum clique
Unbounded from maximum degree
Unbounded from pathwidth
Unbounded from treewidth

maximum clique

[?]

The parameter maximum clique of a graph $G$ is the largest number of vertices in a complete subgraph of $G$.

Unbounded

Unbounded on complete [by definition]

maximum degree

[?]

The maximum degree of a graph $G$ is the largest number of neighbors of a vertex in $G$.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from maximum clique

Unbounded on (C₄,P₃,triangle)-free [by definition]
Unbounded on complete [by definition]

maximum independent set

[?]

An independent set of a graph $G$ is a subset of pairwise non-adjacent vertices. The parameter maximum independent set of graph $G$ is the size of a largest independent set in $G$.

Unbounded

Unbounded from maximum induced matching
Unbounded from minimum dominating set

maximum induced matching

[?]

For a graph $G = (V,E)$ an induced matching is an edge subset $M \subseteq E$ that satisfies the following two conditions: $M$ is a matching of the graph $G$ and there is no edge in $E \backslash M$ connecting any two vertices belonging to edges of the matching $M$. The parameter maximum induced matching of a graph $G$ is the largest size of an induced matching in $G$.

Unbounded

Unbounded on maximum degree 1 [trivial]

maximum matching

[?]

A matching in a graph is a subset of pairwise disjoint edges (any two edges that do not share an endpoint). The parameter maximum matching of a graph $G$ is the largest size of a matching in $G$.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from book thickness
Unbounded from branchwidth
Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from distance to block
Unbounded from distance to cluster
Unbounded from distance to co-cluster
Unbounded from distance to cograph
Unbounded from distance to linear forest
Unbounded from distance to outerplanar
Unbounded from maximum clique
Unbounded from maximum induced matching
Unbounded from pathwidth
Unbounded from tree depth
Unbounded from treewidth
Unbounded from vertex cover

minimum clique cover

[?]

A clique cover of a graph $G = (V, E)$ is a partition $P$ of $V$ such that each part in $P$ induces a clique in $G$. The minimum clique cover of $G$ is the minimum number of parts in a clique cover of $G$. Note that the clique cover number of a graph is exactly the chromatic number of its complement.

Unbounded

Unbounded from maximum independent set
Unbounded from maximum induced matching
Unbounded from minimum dominating set

minimum dominating set

[?]

A dominating set of a graph $G$ is a subset $D$ of its vertices, such that every vertex not in $D$ is adjacent to at least one member of $D$. The parameter minimum dominating set for graph $G$ is the minimum number of vertices in a dominating set for $G$.

Unbounded

Unbounded on K₂-free [by definition]

pathwidth

[?]

A path decomposition of a graph $G$ is a pair $(P,X)$ where $P$ is a path with vertex set $\{1, \ldots, q\},ドル and $X = \{X_1,X_2, \ldots ,X_q\}$ is a family of vertex subsets of $V(G)$ such that:

$\bigcup_{p \in \{1,\ldots ,q\}} X_p = V(G)$
$\forall\{u,v\} \in E(G) \exists p \colon u, v \in X_p$
$\forall v \in V(G)$ the set of vertices $\{p \mid v \in X_p\}$ is a connected subpath of $P$.

The width of a path decomposition $(P,X)$ is max$\{|X_p| - 1 \mid p \in \{1,\ldots ,q\}\}$. The pathwidth of a graph $G$ is the minimum width among all possible path decompositions of $G$.

Unbounded

rankwidth

[?]

Let $M$ be the $|V| \times |V|$ adjacency matrix of a graph $G$. The cut rank of a set $A \subseteq V(G)$ is the rank of the submatrix of $M$ induced by the rows of $A$ and the columns of $V(G) \backslash A$. A rank decomposition of a graph $G$ is a pair $(T,L)$ where $T$ is a binary tree and $L$ is a bijection from $V(G)$ to the leaves of the tree $T$. Any edge $e$ in the tree $T$ splits $V(G)$ into two parts $A_e, B_e$ corresponding to the leaves of the two connected components of $T - e$. The width of an edge $e \in E(T)$ is the cutrank of $A_e$. The width of the rank-decomposition $(T,L)$ is the maximum width of an edge in $T$. The rankwidth of the graph $G$ is the minimum width of a rank-decomposition of $G$.

Bounded

Bounded from booleanwidth
Bounded from cliquewidth
Bounded from rankwidth on the complement

tree depth

[?]

A tree depth decomposition of a graph $G = (V,E)$ is a rooted tree $T$ with the same vertices $V,ドル such that, for every edge $\{u,v\} \in E,ドル either $u$ is an ancestor of $v$ or $v$ is an ancestor of $u$ in the tree $T$. The depth of $T$ is the maximum number of vertices on a path from the root to any leaf. The tree depth of a graph $G$ is the minimum depth among all tree depth decompositions.

Unbounded

treewidth

[?]

A tree decomposition of a graph $G$ is a pair $(T, X),ドル where $T = (I, F)$ is a tree, and $X = \{X_i \mid i \in I\}$ is a family of subsets of $V(G)$ such that

the union of all $X_i,ドル $i \in I$ equals $V,ドル
for all edges $\{v,w\} \in E,ドル there exists $i \in I,ドル such that $v, w \in X_i,ドル and
for all $v \in V$ the set of nodes $\{i \in I \mid v \in X_i\}$ forms a subtree of $T$.

The width of the tree decomposition is $\max |X_i| - 1$.
The treewidth of a graph is the minimum width over all possible tree decompositions of the graph.

Unbounded

vertex cover

[?]

Let $G$ be a graph. Its vertex cover number is the minimum number of vertices that have to be deleted in order to obtain an independent set.

Unbounded

Unbounded from acyclic chromatic number
Unbounded from book thickness
Unbounded from branchwidth
Unbounded from chromatic number
Unbounded from degeneracy
Unbounded from distance to block
Unbounded from distance to cluster
Unbounded from distance to co-cluster
Unbounded from distance to cograph
Unbounded from distance to linear forest
Unbounded from distance to outerplanar
Unbounded from maximum clique
Unbounded from maximum induced matching
Unbounded from maximum matching
Unbounded from pathwidth
Unbounded from tree depth
Unbounded from treewidth

Problems

Problems in italics have no summary page and are only listed when ISGCI contains a result for the current class.

Parameter decomposition

book thickness decomposition

[?]

Input: A graph G in this class and an integer k.

Output: True iff the book thickness of G is at most k.

Unknown to ISGCI

booleanwidth decomposition

[?]

Input: A graph G in this class.

Output: An expression that constructs G according to the rules for booleanwidth, using only a constant number of labels.
Undefined if this class has unbounded booleanwidth.

Polynomial

Polynomial from Bounded booleanwidth

cliquewidth decomposition

[?]

Input: A graph G in this class.

Output: An expression that constructs G according to the rules for cliquewidth, using only a constant number of labels.
Undefined if this class has unbounded cliquewidth.

Linear

Polynomial from Bounded cliquewidth
Polynomial from cliquewidth decomposition on the complement

Linear on (5,1)

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Linear on (7,3)

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Linear on (9,6)

[488]

A. Gy\'arf\'as, D. Kratsch, J. Lehel, F. Maffray
Minimal non--neighbourhood--perfect graphs
J. Graph Theory 21 55--66 1996

Linear on (P,P,co-fork,fork)-free

[1185]

A. Brandstaedt, F.F. Dragan, H.-O. Le, R. Mosca
New graph classes of bounded clique-width
WG 2002, Lecture Notes in Computer Science 2573, 57-67 (2002)

Linear on P₄-tidy

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Linear on (P₅,fork,house)-free

[1185]

A. Brandstaedt, F.F. Dragan, H.-O. Le, R. Mosca
New graph classes of bounded clique-width
WG 2002, Lecture Notes in Computer Science 2573, 57-67 (2002)

[402]

J.L. Fouquet, V. Giakoumakis
On semi--$P_4$--sparse graphs
Discrete Math. 165/166 1997 277--300

Linear on (P,fork,house)-free

[1185]

A. Brandstaedt, F.F. Dragan, H.-O. Le, R. Mosca
New graph classes of bounded clique-width
WG 2002, Lecture Notes in Computer Science 2573, 57-67 (2002)

[1186]

A. Brandstaedt, R. Mosca
On variations of P_4-sparse graphs.
Manuscript 2001

Linear on partner-limited

[1179]

J.M. Vanherpe
Clique-width of partner-limited graphs.
International Conference of Graph Theory, Marseille 2000

Linear on (q, q-3), fixed q>= 7

[1176]

J.A. Makowsky, U. Rotics
On the clique-width of graphs with few $P_4$'s.
International Journal of Foundations of Computer Science 10 (1999) 329-348

Linear on (q,q-4), fixed q

[1175]

B. Courcelle, J.A. Makowsky, U. Rotics
Linear time optimization problems on graphs of bounded clique width.
Theory of Computing Systems 33 (2000) 125-150

Linear on semi-P₄-sparse

[1186]

A. Brandstaedt, R. Mosca
On variations of P_4-sparse graphs.
Manuscript 2001

cutwidth decomposition

[?]

Input: A graph G in this class and an integer k.

Output: True iff the cutwidth of G is at most k.

Unknown to ISGCI

treewidth decomposition

[?]

Input: A graph G in this class and an integer k.

Output: True iff the treewidth of G is at most k.

Polynomial

Polynomial on HHD-free

[1420]

H.J. Broersma, E. Dahlhaus, T. Kloks
Algorithms for the treewidth and minimum fill-in of HHD-free graphs
23rd Intern. Workshop on Graph--Theoretic Concepts in Comp. Sci. WG'97, Lecture Notes in Comp. Sci. 1335 (1997) 109-117

Polynomial on (q,q-4), fixed q

[1422]

L. Babel
Triangulating graphs with few P4's
Disc. Appl. Math. 89 45-57 (1998)

Polynomial [$O((V+E) \log V)$] on weak bipolarizable

[1419]

E. Dahlhaus
Minimum fill-in and treewidth on graphs modularly decomposable into chordal graphs
24th Intern. Workshop on Graph--Theoretic Concepts in Comp. Sci. WG'98, Lecture Notes in Comp. Sci. 1517 (1998) 351-358

Polynomial on weakly chordal

[1421]

V. Bouchitte, I. Todinca
Treewidth and minimum fill-in of weakly triangulated graphs
Annual symposium on theoretical aspects of computer science STACS 99, Lecture Notes in Comp. Sci. 1563 (1999) 197-206

Unweighted problems

3-Colourability

[?]

Input: A graph G in this class.

Output: True iff each vertex of G can be assigned one colour out of 3 such that whenever two vertices are adjacent, they have different colours.

Linear

Linear from Colourability
Linear from FPT-Linear on cliquewidth and Linear decomposition time
Polynomial from Colourability
Polynomial from FPT on booleanwidth and Polynomial decomposition time
Polynomial from FPT on rankwidth and Linear decomposition time
Polynomial from FPT-Linear on cliquewidth and Polynomial decomposition time

Polynomial on 2P₃-free

[1431]

H. Broersma, P.A. Golovach, D. Paulusma, J. Song
Determining the chromatic number of triangle-free 2P3-free graphs in polynomial time
Manuscript (2010)

Polynomial on P₂ ∪ P₄-free

[1431]

H. Broersma, P.A. Golovach, D. Paulusma, J. Song
Determining the chromatic number of triangle-free 2P3-free graphs in polynomial time
Manuscript (2010)

Polynomial on P₅-free

[1242]

B. Randerath, I. Schiermeyer, M. Tewes
Three-colourability and forbidden subgraphs II: polynomial algorithms
Discrete Math. 251 137-212 (2002)

[1441]

C.T. Hoang, M. Kaminski, V. Lozin, J. Sawada, X. Shu
Deciding k-colorability of P_5-free graphs in polynomial time
Algorithmica Vol.57 No.1 74-81 (2010)

Polynomial on P₆-free

[1243]

B. Randerath, I. Schiermeyer
3-colorability in P for P_6-free graphs
Discrete Appl. Math. 136 299-313 (2004)

Polynomial on nP₃-free, fixed n

[1431]

H. Broersma, P.A. Golovach, D. Paulusma, J. Song
Determining the chromatic number of triangle-free 2P3-free graphs in polynomial time
Manuscript (2010)

Polynomial on odd-hole-free

[1744]

(no preview available)

Clique

[?]

Input: A graph G in this class and an integer k.

Output: True iff G contains a set S of pairwise adjacent vertices, with |S| >= k.

Linear

Polynomial from FPT on booleanwidth and Polynomial decomposition time
Polynomial from FPT on cliquewidth and Linear decomposition time
Polynomial from FPT on cliquewidth and Polynomial decomposition time
Polynomial from FPT on rankwidth and Linear decomposition time
Polynomial from Independent set on the complement
Polynomial from Weighted clique

Linear on Matula perfect

[221]

V. Chv\'atal, C.T. Ho\`ang, N.V.R. Mahadev, D. de Werra
Four classes of perfectly orderable graphs
J. Graph Theory 11 1987 481--495

Linear on Welsh-Powell perfect

[221]

V. Chv\'atal, C.T. Ho\`ang, N.V.R. Mahadev, D. de Werra
Four classes of perfectly orderable graphs
J. Graph Theory 11 1987 481--495

Polynomial on b-perfect

[1478]

C.T. Hoang, F. Maffray, M. Mechebbek
A characterization of b-perfect graphs
Manuscript, 2010

Polynomial on biclique separable

[1304]

Eschen, Elaine M.; Hoàng, Chính T.; Petrick, Mark D.T.; Sritharan, R
Disjoint clique cutsets in graphs without long holes
J. Graph Theory 48, No.4, 277-298 (2005)

Polynomial on circular perfect

[1408]

A. Pecher, A.K. Wagler
Clique and chromatic number of circular-perfect graphs
Proceedings of ISCO 2010 - International Symposium on Combinatorial Optimization, Elec. Notes in Discrete Math 36 199-206 (2010)

Clique cover

[?]

Input: A graph G in this class and an integer k.

Output: True iff the vertices of G can be partitioned into k sets S_i, such that whenever two vertices are in the same set S_i, they are adjacent.

Polynomial

Polynomial from Colourability on the complement
Polynomial from XP on booleanwidth and Polynomial decomposition time
Polynomial from XP on cliquewidth and Linear decomposition time
Polynomial from XP on cliquewidth and Polynomial decomposition time
Polynomial from XP on rankwidth and Linear decomposition time

Colourability

[?]

Input: A graph G in this class and an integer k.

Output: True iff each vertex of G can be assigned one colour out of k such that whenever two vertices are adjacent, they have different colours.

Linear

Polynomial from Clique cover on the complement
Polynomial from FPT on booleanwidth and Polynomial decomposition time
Polynomial from FPT on cliquewidth and Linear decomposition time
Polynomial from FPT on cliquewidth and Polynomial decomposition time
Polynomial from FPT on rankwidth and Linear decomposition time

Linear on Matula perfect

[221]

V. Chv\'atal, C.T. Ho\`ang, N.V.R. Mahadev, D. de Werra
Four classes of perfectly orderable graphs
J. Graph Theory 11 1987 481--495

Linear on Welsh-Powell perfect

[221]

V. Chv\'atal, C.T. Ho\`ang, N.V.R. Mahadev, D. de Werra
Four classes of perfectly orderable graphs
J. Graph Theory 11 1987 481--495

Polynomial on b-perfect

[1478]

C.T. Hoang, F. Maffray, M. Mechebbek
A characterization of b-perfect graphs
Manuscript, 2010

Polynomial on biclique separable

[1304]

Eschen, Elaine M.; Hoàng, Chính T.; Petrick, Mark D.T.; Sritharan, R
Disjoint clique cutsets in graphs without long holes
J. Graph Theory 48, No.4, 277-298 (2005)

Polynomial on circular perfect

[1408]

Polynomial on perfect

[476]

M. Gr\"otschel, L. Lov\'asz, A. Schrijver
The ellipsoid method and its consequences in combinatorial optimization
Combinatorica 1 169--197, 1981 Corrigendum

Polynomial [$O(VE)$] on perfectly orderable
Polynomial [$O(V^4E)$] on weakly chordal

[530]

R.B. Hayward, C. Ho\`ang, F. Maffray
Optimizing weakly triangulated graphs
Graphs and Combinatorics 5 339--349, Erratum: 6 (1990) 33--35 1989

Domination

[?]

Input: A graph G in this class and an integer k.

Output: True iff G contains a set S of vertices, with |S| <= k, such that every vertex in G is either in S or adjacent to a vertex in S.

Linear

Linear from FPT-Linear on cliquewidth and Linear decomposition time
Polynomial from FPT on booleanwidth and Polynomial decomposition time
Polynomial from FPT on rankwidth and Linear decomposition time
Polynomial from FPT-Linear on cliquewidth and Polynomial decomposition time

Feedback vertex set

[?]

Input: A graph G in this class and an integer k.

Output: True iff G contains a set S of vertices, with |S| <= k, such that every cycle in G contains a vertex from S.

Linear

Linear from Weighted feedback vertex set
Polynomial from FPT on booleanwidth and Polynomial decomposition time
Polynomial from FPT on cliquewidth and Linear decomposition time
Polynomial from FPT on cliquewidth and Polynomial decomposition time
Polynomial from FPT on rankwidth and Linear decomposition time
Polynomial from Weighted feedback vertex set

Polynomial on chordal ∪ co-chordal

Graph isomorphism

[?]

Input: Graphs G and H in this class

Output: True iff G and H are isomorphic.

Polynomial

Polynomial from Graph isomorphism on the complement
Polynomial from XP on booleanwidth and Polynomial decomposition time
Polynomial from XP on cliquewidth and Linear decomposition time
Polynomial from XP on cliquewidth and Polynomial decomposition time
Polynomial from XP on rankwidth and Linear decomposition time

Hamiltonian cycle

[?]

Input: A graph G in this class.

Output: True iff G has a simple cycle that goes through every vertex of the graph.

Polynomial

Polynomial from XP on booleanwidth and Polynomial decomposition time
Polynomial from XP on cliquewidth and Linear decomposition time
Polynomial from XP on cliquewidth and Polynomial decomposition time
Polynomial from XP on rankwidth and Linear decomposition time

Hamiltonian path

[?]

Input: A graph G in this class.

Output: True iff G has a simple path that goes through every vertex of the graph.

Polynomial

Independent dominating set

[?]

Input: A graph G in this class and an integer k.

Output: True iff G contains a set S of pairwise non-adjacent vertices, with |S| <= k, such that every vertex in G is either in S or adjacent to a vertex in S.

Linear

Linear from Weighted independent dominating set
Polynomial from Weighted independent dominating set

Independent set

[?]

Input: A graph G in this class and an integer k.

Output: True iff G contains a set S of pairwise non-adjacent vertices, such that |S| >= k.

Linear

Linear from Weighted independent set
Polynomial from Clique on the complement
Polynomial from FPT on booleanwidth and Polynomial decomposition time
Polynomial from FPT on cliquewidth and Linear decomposition time
Polynomial from FPT on cliquewidth and Polynomial decomposition time
Polynomial from FPT on rankwidth and Linear decomposition time
Polynomial from Weighted independent set

Linear on P₄-tidy

[440]

V. Giakoumakis, F. Roussel, H. Thuillier
On $P_4$--tidy graphs
Discrete Math. and Theor. Comp. Sci. 1 1997 17--41

Linear on extended P₄-laden

[438]

V. Giakoumakis
$P_4$--laden graphs: a new class of brittle graphs
Inf. Proc. Letters 60 1996 29--36

Linear on partner-limited

[1180]

F. Roussel, I. Rusu, H. Thuillier
On graphs with limited number of P_4-partners.
International Journal of Foundations of Computer Science, 1o 103-121 (1999)

Polynomial on (C₅,P₅,P₂ ∪ P₃)-free

[1118]

M.U. Gerber, V.V. Lozin
On the stable set problem in special P_5-free graphs.
Rutcor Research Report 24-2000

Polynomial on (C₆,K_3,3+e,P,P₇,X₃₇,X₄₁)-free

[1346]

N.V.R. Mahadev, B.A. Reed
A note on vertex orders for stability number
J. Graph Theory 30 113-120 (1999)

Polynomial on (E,P)-free

[1305]

M.U. Gerber, V.V. Lozin
Robust algorithms for the stable set problem
Graphs and Combin., to appear

Polynomial on (K_2,3,P,P₅)-free

[1107]

N.V.R. Mahadev
Vertex deletion and stability number
Research report ORWP 90/2 Dept. of Mathematics, Swiss Fed.Inst. of Technology 1990

[1346]

N.V.R. Mahadev, B.A. Reed
A note on vertex orders for stability number
J. Graph Theory 30 113-120 (1999)

Polynomial [$O(nm)$] on (K_3,3-e,P₅,X₉₈)-free

[1117]

A. Brandstaedt, V.V. Lozin
A note on \alpha-redundant vertices in graphs.
Discrete Appl. Math. 108 (2001) 301-308

Polynomial [$O(V^{5})$] on (K_3,3-e,P₅,X₉₉)-free

[1307]

M.U. Gerber, A. Hertz, D. Schindl
P_5-free graphs and the maximum stable set problem
Discrete Appl. Math. 132 109-119 (2004)

Polynomial on (K_3,3-e,P₅)-free

[1246]

V. Alekseev, P. Lozin, R. Mosca
Maximum independent set problem and P_5-free graphs
Manuscript 2004

Polynomial on Meyniel

[169]

M. Burlet, J. Fonlupt
Polynomial algorithm to recognize a Meyniel graph
Annals of Discrete Math. 21 1984 225--252

Polynomial [$O(VE)$] on (P,P₅)-free

[1117]

A. Brandstaedt, V.V. Lozin
A note on \alpha-redundant vertices in graphs.
Discrete Appl. Math. 108 (2001) 301-308

Polynomial [$O(V^8)$] on (P,P₇)-free

[1351]

V.E. Alekseev, V.V. Lozin
Augmenting graphs for independent sets
Discrete Appl. Math. 145, No.1 3-10 (2004)

Polynomial on (P,P₈)-free

[1306]

M.U. Gerber, A. Hertz, V.V. Lozin
Stable sets in two subclasses of banner-free graphs
Discrete Appl. Math. 132 121-136 (2004)

Polynomial on (P,T₂)-free

[1305]

M.U. Gerber, V.V. Lozin
Robust algorithms for the stable set problem
Graphs and Combin., to appear

Polynomial on (P,star_1,2,5)-free

[1349]

V.L. Lozin, M. Milanic
On finding augmenting graphs
Rutcor Research Report 28-2005

Polynomial on (P₅,P₂ ∪ P₃)-free

[1350]

V.E. Alekseev
On easy and hard hereditary classes of graphs with respect to the independent set problem
Discrete Appl. Math. 132, No.1-3 17-26 (2003)

Polynomial on co-biclique separable

[1304]

Eschen, Elaine M.; Hoàng, Chính T.; Petrick, Mark D.T.; Sritharan, R
Disjoint clique cutsets in graphs without long holes
J. Graph Theory 48, No.4, 277-298 (2005)

Polynomial [$O(VE)$] on weakly chordal

[1119]

R. Hayward, J. Spinrad. R. Sritharan
Weakly chordal graph algorithms via handles
Proc. of the 11th symposium on Discrete Algorithms 42-49, 2000

[530]

R.B. Hayward, C. Ho\`ang, F. Maffray
Optimizing weakly triangulated graphs
Graphs and Combinatorics 5 339--349, Erratum: 6 (1990) 33--35 1989

Maximum cut

[?]

(decision variant)

Input: A graph G in this class and an integer k.

Output: True iff the vertices of G can be partitioned into two sets A,B such that there are at least k edges in G with one endpoint in A and the other endpoint in B.

Polynomial

Polynomial from XP,W-hard on booleanwidth and Polynomial decomposition time
Polynomial from XP,W-hard on cliquewidth and Linear decomposition time
Polynomial from XP,W-hard on cliquewidth and Polynomial decomposition time
Polynomial from XP,W-hard on rankwidth and Linear decomposition time

Polynomial on (q,q-4), fixed q

[1731]

H.L. Bodlaender, C.M.H. de Figueiredo, M. Gutierrez, T. Kloks, R. Niedermeier
Simple max-cut for split-indifference graphs and graphs with few P4s
Proceedings of 3rd Workshop on experimental and efficient algorithms WEA-04, LNCS 3059 87-99 (2004)

Monopolarity

[?]

Input: A graph G in this class.

Output: True iff G is monopolar.

Polynomial

Polynomial [$O(V^4)$] on (5-pan,T₂,X₁₇₂)-free

[1764]

V.B. Le, R. Nevries
Complexity and algorithms for recognizing polar and monopolar graphs
Theoretical Computer Science 528 1-11 (2014)

Polynomial on hole-free

[1764]

V.B. Le, R. Nevries
Complexity and algorithms for recognizing polar and monopolar graphs
Theoretical Computer Science 528 1-11 (2014)

Polarity

[?]

Input: A graph G in this class.

Output: True iff G is polar.

Polynomial

Polynomial from Polarity on the complement
Polynomial from XP on booleanwidth and Polynomial decomposition time
Polynomial from XP on cliquewidth and Linear decomposition time
Polynomial from XP on cliquewidth and Polynomial decomposition time
Polynomial from XP on rankwidth and Linear decomposition time

Polynomial on chordal ∪ co-chordal

Recognition

[?]

Input: A graph G.

Output: True iff G is in this graph class.

Linear

[1058]

R.I. Tyshkevich, A.A. Chernyak, Zh. A. Chernyak
Graphs and degree sequences II
Cybernetics (the English translation of Kibernetika) 24 1988 137--152

Polynomial on (C₅,K₂ ∪ K₃,K_2,3,P,P₂ ∪ P₃,P₅,P,P₂ ∪ P₃,co-fork,fork,house)-free

Weighted problems

Weighted clique

[?]

Input: A graph G in this class with weight function on the vertices and a real k.

Output: True iff G contains a set S of pairwise adjacent vertices, such that the sum of the weights of the vertices in S is at least k.

Polynomial

Polynomial from FPT on booleanwidth and Polynomial decomposition time
Polynomial from FPT on cliquewidth and Linear decomposition time
Polynomial from FPT on cliquewidth and Polynomial decomposition time
Polynomial from FPT on rankwidth and Linear decomposition time
Polynomial from Weighted independent set on the complement

Polynomial [$O(VE)$] on perfectly orderable

Weighted feedback vertex set

[?]

Input: A graph G in this class with weight function on the vertices and a real k.

Output: True iff G contains a set S of vertices, such that the sum of the weights of the vertices in S is at most k and every cycle in G contains a vertex from S.

Linear

Weighted independent dominating set

[?]

Input: A graph G in this class with weight function on the vertices and a real k.

Output: True iff G contains a set S of pairwise non-adjacent vertices, with the sum of the weights of the vertices in S at most k, such that every vertex in G is either in S or adjacent to a vertex in S.

Linear

Weighted independent set

[?]

Input: A graph G in this class with weight function on the vertices and a real k.

Output: True iff G contains a set S of pairwise non-adjacent vertices, such that the sum of the weights of the vertices in S is at least k.

Linear

[1290]

V. Lozin, R. Mosca
Independent sets and extensions of 2K_2-free graphs
Discrete Appl. Math. 146 74-80 (2005)

Polynomial on (K_2,3,P,P₅)-free

[1107]

N.V.R. Mahadev
Vertex deletion and stability number
Research report ORWP 90/2 Dept. of Mathematics, Swiss Fed.Inst. of Technology 1990

Polynomial on (K_2,3,P,hole)-free

[1107]

N.V.R. Mahadev
Vertex deletion and stability number
Research report ORWP 90/2 Dept. of Mathematics, Swiss Fed.Inst. of Technology 1990

Polynomial on (K_2,3,P₅)-free

[1110]

R. Mosca
Polynomial algorithms for the maximum stable set problem on particular classes of P_5-free graphs
Information Processing Letters 61 (1997) 137-144

Polynomial [$O(n^6)$] on (K_3,3,P₅)-free
Polynomial [$O(n^8)$] on (K_4,4,P₅)-free
Polynomial on (P,P₅)-free

[1353]

A. Brandstaedt, C.T. Hoang
On clique separators, nearly chordal graphs, and the Maximum Weight Stable Set Problem
Theoretical Comp. Sci. 389, No.1-2, 295-306 (2007)

Polynomial [$O(V^9 E)$] on (P,P₇)-free

[1452]

R. Mosca
Stable sets of maximum weight in (P_7, banner)-free graphs
Discrete Math. 308 Issue 1 20-33 (2008)

Polynomial on (P₅,X₈₂,X₈₃)-free

[1246]

V. Alekseev, P. Lozin, R. Mosca
Maximum independent set problem and P_5-free graphs
Manuscript 2004

Polynomial on (P₅,co-fork)-free

[1161]

A. Brandstaedt, R. Mosca
On the structure and stability number of P_5 and co-chair-free graphs.
To appear in Discrete Appl. Math.

Polynomial [$O(VE)$] on (P₅,fork)-free

[1125]

A. Brandstaedt, V.B. Le, H.N. de Ridder
Efficient robust algorithms for the maximum weight stable set problem in chair-free graph classes.
Universitaet Rostock, Fachbereich Informatik, Preprint CS-14-01

Polynomial on (P₅,house)-free

[1109]

V. Giakoumakis, I. Rusu
Weighted parameters in (P_5,\overline{P_5})-free graphs
Discrete Appl. Math. 80 (1997) 255-261

Polynomial on P₅-free

[1635]

D. Lokshantov, M. Vatshelle, Y. Villanger
Independent set in P5-free graphs in polynomial time
Accepted for publication

Polynomial on P₆-free

[1839]

A. Grzesik, T. Klimosova, M. Pilipczuk
Polynomial-time Algorithm for Maximum Weight Independent Set on P6-free Graphs
ACM Transactions on Algorithms 18 No.1 1-57 (2022)

Polynomial [$O(VE)$] on (P,fork)-free

[1125]

Polynomial on (co-fork,hole)-free

[1494]

A. Brandstaedt, V. Giakoumakis
Maximum Weight Independent Sets in Hole- and Co-Chair-Free Graphs
Inform. Proc. Lett. 112 67-71 (2012)

Polynomial on fork-free

[1099]

V.E. Alekseev
A polynomial algorithm for finding maximum independent sets in fork-free graphs
Discrete Ann. Operation Res., Ser. 1 6 (1999) 3-19 (in Russian)

Polynomial on (n+4)-pan-free

[1447]

A. Brandstaedt, V.V. Lozin, R. Mosca
Independent sets of maximum weight in apple-free graphs
SIAM J. Discrete Math. Vol.24 No.1 239-254 (2010)

Polynomial on perfect

[476]

M. Gr\"otschel, L. Lov\'asz, A. Schrijver
The ellipsoid method and its consequences in combinatorial optimization
Combinatorica 1 169--197, 1981 Corrigendum

Polynomial on semi-P₄-sparse

[402]

J.L. Fouquet, V. Giakoumakis
On semi--$P_4$--sparse graphs
Discrete Math. 165/166 1997 277--300

Polynomial [$O(V^4)$] on weakly chordal

[997]

J.P. Spinrad, R. Sritharan
Algorithms for weakly triangulated graphs
Discrete Appl. Math. 59 1995 181--191

Weighted maximum cut

[?]

(decision variant)

Input: A graph G in this class with weight function on the edges and a real k.

Output: True iff the vertices of G can be partitioned into two sets A,B such that the sum of weights of the edges in G with one endpoint in A and the other endpoint in B is at least k.

NP-complete

NP-complete on 2K₁-free

[1676]

M. Kaminski
Max-cut and containment relations in graphs
Proceedings of WG 2010, Lecture Notes in Computer Science 6410, 15-26 (2010)

Graphclass: matroidal

References

Equivalent classes

Complement classes

Related classes

Inclusions

Map

Minimal superclasses

Maximal subclasses

Speed

Parameters

Problems

Parameter decomposition

Unweighted problems

Weighted problems