DM
2010
13 years 11 months ago
2010
Jarik Nesetril suggested to the first author the investigation of notions of homogeneity for relational structures, where "isomorphism" is replaced by "homomorphism...
DM
2010
13 years 11 months ago
2010
We answer the following question of R. L. Graham: What is the discrepancy of the lexicographically-least binary de Bruijn sequence? Here, "discrepancy" refers to the max...
DM
2010
13 years 11 months ago
2010
DM
2010
13 years 11 months ago
2010
A 2-cover is a multiset of subsets of [n] := {1, 2, . . . , n} such that each element of [n] lies in exactly two of the subsets. A 2-cover is called proper if all of the subsets o...
DM
2010
13 years 11 months ago
2010
DM
2010
13 years 11 months ago
2010
We prove that every planar graph in which no i-cycle is adjacent to a j-cycle whenever 3 i j 7 is 3-colorable and pose some related problems on the 3-colorability of planar grap...
DM
2010
13 years 11 months ago
2010
DM
2010
13 years 11 months ago
2010
DM
2010
13 years 11 months ago
2010
The Grundy number of a graph G, denoted by (G), is the largest k such that G has a greedy k-colouring, that is a colouring with k colours obtained by applying the greedy algorithm...
DM
2010
13 years 11 months ago
2010
Given a metric d on a permutation group G, the corresponding weight problem is to decide whether there exists an element G such that d(, e) = k, for some given value k. Here we ...