Douglas-Rachford for Combinatorial Optimization

AUTHORS: Francisco J. Aragón Artacho, Jonathan M. Borwein, Matthew K. Tam.

CONTACT:

This is the companion webpage for "Recent Results on Douglas-Rachford Methods for Combinatorial Optimization Problems" (preprint).

1. Interactive Cinderella applets
• Douglas-Rachford 2-cycles for a half-line and a circle
2. A 'Nasty' Sudoku
• The 'nasty' Sudoku and its unique solution (found with Douglas-Rachford).
• Five solutions to the 'nasty' Sudoku with the top-left entry removed (found with SudokuSolver).
3. Sudoku Test Libraries
• ksudoku16 - contains 16 by 16 instances generated with KSudoku.
• ksudoku25 - contains 25 by 25 instances generated with KSudoku.
• Dukuso's top95 and top1465 - contains 9 by 9 instances frequently used by programmers for testing.
• Gordon Royle's mimimum Sudoku - contains 9 by 9 instances with 17 entries (best known lower bound for a unique solution).
• reglib-1.3 - contains 9 by 9 instances suited to various human-style techniques.
4. Sudoku Solvers
• Our Douglas-Rachford implementation (C++). For a copy of the source code, contact .