exact-cover (hackage): Fast solver for exact set cover problems (http://en.wikipedia.org/wiki/Exact_cover) using Algorithm X as described in the paper Dancing Links, by Donald Knuth, in Millennial Perspectives in Computer Science, P159, 2000 (https://arxiv.org/abs/cs/0011047).  To get started, see the documentation for the Math.ExactCover module below.  Build examples with cabal install -fbuildExamples or stack build --flag exact-cover:buildExamples. Examples include a Sudoku solver.
Keywords: algorithms|bsd3|library|math