CompleteQ[g] yields True if graph g is complete. This means that between any pair of vertices there is an undirected edge or two directed edges going in opposite directions.

Compositions[n, k] gives a list of all compositions of integer n into k parts.

CoxeterGraph gives a non-Hamiltonian graph with a high degree of symmetry such that there is a graph automorphism taking any path of length 3 to any other.

CycleStructure[p, x] returns the monomial in x[1], x[2], ..., x[Length[p]] that is the cycle structure of the permutation p.

CyclicGroupIndex[n, x] returns the cycle index of the cyclic group on n symbols, expressed as a polynomial in x[1], x[2], ..., x[n].

Cyclic is an argument to the Polya-theoretic functions ListNecklaces, NumberOfNecklaces, and NecklacePolynomial, which count or enumerate distinct necklaces. Cyclic refers to ...

DegreeSequence[g] gives the sorted degree sequence of graph g.

Diameter[g] gives the diameter of graph g, the maximum length, among all pairs of vertices in g, of a shortest path between each pair.

DihedralGroupIndex[n, x] returns the cycle index of the dihedral group on n symbols, expressed as a polynomial in x[1], x[2], ..., x[n].

DihedralGroup[n] returns the dihedral group on n symbols. Note that the order of this group is 2 n.