Hi every one

sorry for my poor english but Sudoku is internationnal

I 'm a french programmer and a new sudokiste

Like many I write my own solver and generator.

Necesessary they are the best one

( Princess Leila tell me that in episode 8)

I program nacked pairs, X wing like thousand programmers

But the challenge is not complex: you have a list of techniques, well explained and you just have to code them.

So I try to find new challenge. Going on the Gordon site to get 36600 17 clues grids to try to make thefirst 16 clues grid of the worrld

Gordon says:

Starting from a grid you can make a lot of permutations, rotations, inversions... with rows, blocks, colonns... It's true

And the result is very different of the original grid.

And he said 'In my list there no such grid'. All the grids are original!

I ask him the question How he does?

But he is perhaps in holiday or with his baby

So I don't know the method. I have begin to search on the net but I don't found a forum or an idea.

So I code a first version of my solution

But it's not perfect so I imagine to ask the question to everybody

Contacting the moderateur of this forum he accept that I subpmit to you the challenge

t's just a game not a competition to say 'I am beter' Like Olympique games the interet is participate not win! (but win is good!)

Searching first elements to begin an idea have appair:

If we can find a original grids after a big checker we can use the technique to sign the grid. The interest is just to say: It's my baby. I work hard to make the first 16 clues grid with only one number reveled!

You don't have to be coder to participate The idea of every one could be THE idea.

To begin the tropic I give you the state of my work and the way I choose.

To work i got the Gordon collectio with 17 clues (the minimum)

( Just for the fun I run my solver : All the grids are godd I HAVE the 36600 solutions)(three or four hours)

In fact when you have a grid you can begin by forget the latin square. You don't have it yet. So you have to deal with the clues

The clues are in a 9x9 matrix 9 rows and 9 colons

to acces to one cell of the grid you need 18 diferents values. The first case of R1 and C1 is common so you have 17 reference: It's the explication why you never find a 16 clues grid: you cannot acces to every cells!

So we can considere that each cell of the grid will be acces by XY coordonnates. f(1,1) give for example a 3 in the R1C1. So he first control that we can do is to verifie that each cell is XY accessible. If not the sudoku will be bad.

I heard the firsts voices : Yes but if you have an empty row or empty colon??How to access.

I will not tell you all today. Search with me....

Papy

I hope that this challenge will give you fun

I leave on the border of the sea so SSS