February contest

Post the puzzle or solving technique that's causing you trouble and someone will help
What about the February-contest (at the sudoku site), didn't it had multiple solutions?

(as a side note, wouldn't it be a good idea to keep the contests of the previous months online aswell?)
Guest

Posts: 312
Joined: 25 November 2005

Unique solution

Here is the February puzzle:

Code: Select all
`5 6  |  2  |    3     |3    |    4     |9 1 4|-----------------    5|     |9 24   9|  5  |3   8  8 6|     |7------------------     |2 4 9|1    |    8|8    |  3  |  6 2`

Here is the solution:

Code: Select all
`5 6 4|8 2 7|1 9 39 7 1|3 6 5|2 8 42 3 8|9 1 4|6 5 7-----------------7 1 5|4 8 3|9 2 64 2 9|7 5 6|3 1 83 8 6|1 9 2|7 4 5-----------------6 5 3|2 4 9|8 7 11 4 2|6 7 8|5 3 98 9 7|5 3 1|4 6 2`

If you think there was another solution, would you mind posting it here, please?

- Wayne
Pappocom

Posts: 599
Joined: 05 March 2005

Ok, I see what went wrong :/

I had the 4 (of the first column) on row 4 and not on row 5

If I place it at the correct place then I get the same solution...

Altough I did had the correct answer for A, B, C and D (maybe more numbers should be asked in the solution?)

For the record the solution I had (with the 4 at the wrong place!):
Code: Select all
`5 6 4 | 8 2 7 | 1 9 39 7 1 | 3 6 5 | 2 8 42 3 8 | 9 1 4 | 6 - - ------------------------4 1 5 | 7 8 3 | 9 2 67 2 9 | - 5 6 | 3 - 83 8 6 | - 9 2 | 7 - -------------------------6 5 3 | 2 4 9 | 8 - -1 4 2 | 6 7 8 | 5 3 98 9 7 | 5 3 1 | 4 6 2`

(Note, feel free to remove this thread, since this is yet another case of using the wrong starting grid...)
Guest

Posts: 312
Joined: 25 November 2005

Hello [Guest]. Thanks for your post. It's always nice to get a mystery explained.

I don't like overburdening people with copying too many entries, so I think ABCD will do for now, even if some lucky ones do creep by!

About your suggestion for keeping the contest puzzles available on site, I will certainly give it some thought. At the least, I might keep one month's contest puzzle available for the month afterwards. It would be handy for reference purposes, if nothing else.

- Wayne
Pappocom

Posts: 599
Joined: 05 March 2005

I am certain that the February puzzle has only the solution given.

I say this because the Su Doku program I have written, solved it (reaching the same solution) purely logically and without any trial & error.

My program currently uses only 3 solution techniques, but I am developing it to add more.

Anthony Jordan
Guest

Posts: 312
Joined: 25 November 2005