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.
Speed
[?]
The speed of a class $X$ is the function $n \mapsto |X_n|$, 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: |
factorial | [+]Details |
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 | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
branchwidth
[?]
A branch decomposition of a graph $G$ is a pair $(T,\chi)$, 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 $X, E \backslash X$, 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 | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
cliquewidth
[?]
The cliquewidth of a graph is the number of different labels that is needed to construct the graph using the following operations:
|
Bounded | [+]Details | |
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 | [+]Details | |
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 $i = 1, \ldots,n - 1$, 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 | [+]Details | |
degeneracy
[?]
Let $G$ be a graph and consider the following algorithm:
|
Unbounded | [+]Details | |
diameter
[?]
The diameter of a graph $G$ is the length of the longest shortest path between any two vertices in $G$.
|
Bounded | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
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 .
|
Bounded | [+]Details | |
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 | [+]Details | |
distance to outerplanar
[?]
The distance to outerplanar of a graph $G = (V,E)$ is the minumum size of a vertex subset $X \subseteq V$, such that $G[V \backslash X]$ is a outerplanar graph.
|
Unbounded | [+]Details | |
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 | [+]Details | |
max-leaf number
[?]
The max-leaf number of a graph $G$ is the maximum number of leaves in a spanning tree of $G$.
|
Unbounded | [+]Details | |
maximum clique
[?]
The parameter maximum clique of a graph $G$ is the largest number of vertices in a complete subgraph of $G$.
|
Unbounded | [+]Details | |
maximum degree
[?]
The maximum degree of a graph $G$ is the largest number of neighbors of a vertex in $G$.
|
Unbounded | [+]Details | |
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 | [+]Details | |
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 $G$.
|
Bounded | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
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 | [+]Details | |
pathwidth
[?]
A path decomposition of a graph $G$ is a pair $(P,X)$ where $P$ is a path with vertex set $\{1, \ldots, q\}$, and $X = \{X_1,X_2,
\ldots ,X_q\}$ is a family of vertex subsets of $V(G)$ such that:
|
Unbounded | [+]Details | |
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 | [+]Details | |
tree depth
[?]
A tree depth decomposition of a graph $G = (V,E)$ is a rooted tree $T$ with the same vertices $V$, such that, for every edge
$\{u,v\} \in E$, 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 | [+]Details | |
treewidth
[?]
A tree decomposition of a graph $G$ is a pair $(T, X)$, 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 treewidth of a graph is the minimum width over all possible tree decompositions of the graph. |
Unbounded | [+]Details | |
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 | [+]Details |
Problems in italics have no summary page and are only listed when ISGCI contains a result for the current class.
book thickness decomposition
[?]
|
Unknown to ISGCI | [+]Details | |||||
booleanwidth decomposition
[?]
|
Polynomial | [+]Details | |||||
cliquewidth decomposition
[?]
|
Linear | [+]Details | |||||
cutwidth decomposition
[?]
|
Unknown to ISGCI | [+]Details | |||||
treewidth decomposition
[?]
|
Linear | [+]Details |
3-Colourability
[?]
|
Linear | [+]Details | |||||
Clique
[?]
|
Linear | [+]Details | |||||
Clique cover
[?]
|
Polynomial | [+]Details | |||||
Colourability
[?]
|
Linear | [+]Details | |||||
Domination
[?]
|
Linear | [+]Details | |||||
Feedback vertex set
[?]
|
Linear | [+]Details | |||||
Graph isomorphism
[?]
|
Linear | [+]Details | |||||
Hamiltonian cycle
[?]
|
Linear | [+]Details | |||||
Hamiltonian path
[?]
|
Linear | [+]Details | |||||
Independent dominating set
[?]
|
Linear | [+]Details | |||||
Independent set
[?]
|
Linear | [+]Details | |||||
Maximum cut
[?]
(decision variant)
|
Polynomial | [+]Details | |||||
Monopolarity
[?]
|
Polynomial | [+]Details | |||||
Polarity
[?]
|
Polynomial | [+]Details | |||||
Recognition
[?]
|
Linear | [+]Details |
Weighted clique
[?]
|
Linear | [+]Details | |||||
Weighted feedback vertex set
[?]
|
Linear | [+]Details | |||||
Weighted independent dominating set
[?]
|
Linear | [+]Details | |||||
Weighted independent set
[?]
|
Linear | [+]Details | |||||
Weighted maximum cut
[?]
(decision variant)
|
NP-complete | [+]Details |