Using Conjugate Chain filtering

Puzzler · Posted: Mon Feb 08, 2010 2:36 am Post subject: Using Conjugate Chain filtering

Hi All

One of the key learnings I had when I was developing Starfish Sudoku was the use of coloring to identify conjugate pairs.

This technique was a revelation for me, and I’ve come to rely on it to solve puzzles that were previously way beyond my ability.

I developed filters that analyzed and displayed up to four conjugate pair chains, and then applied one of three color schemes to the chains.

In addition to Simple Coloring and Multi-Coloring, I also implemented Single Coloring and I’ve been pleasantly surprised how useful this is.

The Single Coloring scheme paints all the cells in a conjugate pair chain the same color. So all cells in chain 1 are blue, all cells in chain 2 are green and so on.

These are some examples of how I use Single Coloring.

If anyone has any other ideas for how colouring can be used, I’d love to hear about them

Regards

Puzzler

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Single Coloring reveals Unique Rectangle
In this example, the Unique Rectangle is revealed by chain 3

Single Coloring reveals X-Wing
In this example, the x-wing for 4 is revealed by chains 3 and 4

In this example, the x-wing for 5 is revealed by chains 2 and 3