Tag Archives: coloring cluster extension

Slink vs. Coloring Networks and Illogical Sudoku

This post reports a surprising fact about multiple solution puzzles, that solutions found by backtracking tree search can be logically inconsistent. Specifically, such solutions violate the coloring network implied by the givens. I happened on this fact by means of … Continue reading

Posted in Advanced Solving | Tagged , , , , | 4 Comments

A Run Through Ardson’s Very Hard Volume 2

This post begins a review of A.D. Ardson’s Sudoku Very Hard Puzzles, volume 2. The review will cover 10 pre-selected puzzles from 400, every 40 starting with number 38. Well, almost. The puzzle at the end of the previous post … Continue reading

Posted in Puzzle Reviews | Tagged , , , , , , , | 4 Comments