networkx.generators.sudoku.sudoku_graph¶
-
sudoku_graph
(n=3)[source]¶ Returns the n-Sudoku graph. The default value of n is 3.
The n-Sudoku graph is a graph with n^4 vertices, corresponding to the cells of an n^2 by n^2 grid. Two distinct vertices are adjacent if and only if they belong to the same row, column, or n-by-n box.
- Parameters
n (integer) – The order of the Sudoku graph, equal to the square root of the number of rows. The default is 3.
- Returns
The n-Sudoku graph Sud(n).
- Return type
NetworkX graph
Examples
>>> G = nx.sudoku_graph() >>> G.number_of_nodes() 81 >>> G.number_of_edges() 810 >>> sorted(G.neighbors(42)) [6, 15, 24, 33, 34, 35, 36, 37, 38, 39, 40, 41, 43, 44, 51, 52, 53, 60, 69, 78] >>> G = nx.sudoku_graph(2) >>> G.number_of_nodes() 16 >>> G.number_of_edges() 56
References
- 1
Herzberg, A. M., & Murty, M. R. (2007). Sudoku squares and chromatic polynomials. Notices of the AMS, 54(6), 708-717.
- 2
Sander, Torsten (2009), “Sudoku graphs are integral”, Electronic Journal of Combinatorics, 16 (1): Note 25, 7pp, MR 2529816
- 3
Wikipedia contributors. “Glossary of Sudoku.” Wikipedia, The Free Encyclopedia, 3 Dec. 2019. Web. 22 Dec. 2019.