To get the sample input files:
Or you can get them one at a time (more tedious) from here.
The input files:
The corresponding output files (after running for two minutes):
A (3,g)-cage is a 3-regular graph of girth g that has a minimum possible number of vertices. This input file contains the small cages. The last two graphs are a girth 13 graph on 272 vertices and a girth 14 graph on 384 vertices; it is not known if these last two graphs are cages or if a smaller graph is possible.
Assume that k soccer matchs are being played. Each one can end in a win, a loss or a tie. The pool sells tickets that correspond to choosing an outcome for each of the k games. You win something if you have a ticket that has at least k-1 correct outcomes. A dominating set corresponds to a subset of the possible tickets that guarantees that at least one ticket wins.
The graph that has 3k vertices, each one corresponding to a possible outcome for all of the matches. Two vertices are adjacent if they differ in one position. The input file has football pool problems ranging from 1 to 6 matchings having respectively 3, 9, 27, 81, 243 or 729 vertices. These graphs are vertex transitive.
A hypercube of dimension k has 2k vertices and each vertex is labelled with a different k-bit binary string. Two vertices are adjacent if their binary strings differ in one bit position. Hypercubes have been proposed as a good network topology. For n vertices, the degree of each vertex is relatively small (log2(n)). The input file has hypercubes of dimensions 3 to 9 having 8, 16, 32, 64, 128, 256 and 512 vertices. These graphs are vertex transitive.
The cases in the table are marked with
* to indicate the answer is (n-1)/2.
+ to indicate the answer is the floor of (n+1)/2.
- to indicate the answer is the 1 + floor of (n+1)/2.
Dimension | Min |
---|---|
1 | 1 + |
2 | 1 + |
3 | 1 * |
4 | 2 + |
5 | 3 + |
6 | 3 + |
7 | 4 + |
8 | 5 - |
9 | 5 + |
10 | 5 + |
11 | 5 * |
12 | 6 + |
13 | 7 + |
14 | 8 - |
15 | 9 - |
16 | 9 - |
17 | 9 + |
18 | 9 + |
19 | 10 + |
20 | [10 or 11] |
21 | 11 + |
22 | [11 or 12] |
23 | 12 + |
24 | [12 or 13] |
25 | 13 + |
26 | [13 or 14] |
27 | 14 + |
28 | [14 or 15] |
29 | 15 + |
30 | 15 + |
This wiki page http://mathworld.wolfram.com/KneserGraph.html has a nice description of the Kneser graphs. They are vertex transitive. The number of vertices of each and the degree of each vertex:
As far as I know, the dominating set problem is open for these graphs:
Lower bound | Upper bound | Graph name | Number of vertices | Degrees | Input file |
22 | 27 | Kneser (9,4) | 126 | 5 | ikneser_9_4.txt |
14 | 20 | Kneser (10,4) | 210 | 15 | ikneser_10_4.txt |
10 | 17 | Kneser (11,4) | 330 | 35 | ikneser_11_4.txt |
10 | 12 | Kneser (12,4) | 495 | 70 | ikneser_12_4.txt |
10 | 11 | Queen graph: dimension 20 | 400 | 57-75 | iqueen_20.txt |
11 | 12 | Queen graph: dimension 22 | 484 | 63-83 | iqueen_22.txt |
12 | 13 | Queen graph: dimension 24 | 576 | 69-91 | iqueen_24.txt |
13 | 14 | Queen graph: dimension 26 | 676 | 75-99 | iqueen_26.txt |
58 | 64 | Hypercube dimension 9 | 512 | 9 | ihyper_9.txt |
71 | 73 | Football Pool problem dimension 6 | 729 | 12 | ifootball_6.txt |
Let me know if you find any other small open problems that I can add to this chart.