DC: Disjoint ChainLook at a row, column or box and see if you find x cells containing x numbers. Eg 3 cells [1,3], [1,5], [3,5]. These 3 cells containts the numbers 1,3,5. Therefore 1,3 and 5 must be the solution for these cells, and we can remove them from row, column or box. Here is a sudoku solved as far as possible with the other methods.
here is the solution table this far. R7C2, R7C3 and R9C2 containts the numbers 3, 6 and 8. Therefore we can remove these numbers from the rest of the box. In this case we can remove 3 from R8C1.
By continue using DC on B9 you will be able to solve this sudoku using the other reducing methods. |