The New Sudoku Players' Forum

[Finlip]

Hello Everybody.

My name is Anup Pokhrel. I am a 23 year old student of civil engineering from Kathmandu Nepal. I learnt about this game only last week and have got addicted to it. I learnt about this game through the Kathmandu Post, one of our local English dailies. So far, I am yet to fail to solve a sudoku puzzle from about a dozen that I have attempted.

Today's puzzle in our newspaper was rated Easy but it took over two hours for me to be able to solve it. And for the first time, I had to make a few guesses on my way to solve the puzzle.

??? 34? ??1
??? ??? 5??
?9? 7?6 ??3

?21 ??? 6??
??8 ?6? 9??
??9 ??? 13?

6?? 2?? ?5?
??4 ??? ???
9?? ?53 ???

I was able to solve until I got to

??6 345 ?91
??? ??? 5??
?95 7?6 ??3

?21 ?3? 6??
??8 ?6? 9??
?69 ?7? 13?

6?3 2?? ?5?
??4 6?? 3??
9?? 453 ???

Then I guessed the first line as 2, 8, and 7 even though at this stage all I knew was that the second one couldn't be 2. However, on proceeding I got to the soultion. It was very difficult though this puzzle was rated easy.

I posted this once and it was deleted. I would like to know why. Please let me know. [Comment by Pappocom: Finlip, you posted the same message twice. In deleting one copy, I made a mistake and accidentally deleted both copies. Sorry about that, but please post only one copy of a message.]

[scrose]

Your starting grid has 687 solutions. Either this is a poorly formed sudoku puzzle, or you accidentally left out some clues and/or placed clues in the wrong cells.

A well-formed sudoku puzzle has a unique solution that does not require guessing to reach.

[Finlip]

Your starting grid has 687 solutions. Either this is a poorly formed sudoku puzzle, or you accidentally left out some clues and/or placed clues in the wrong cells.

A well-formed sudoku puzzle has a unique solution that does not require guessing to reach.

Oh sorry I missed a 7 from r7c6.

[scrose]

That missing clue is exactly what is needed to give both of your posted grids a unique solution.

After placing the 7 in r7c6, look for a pair in column 2 and make some eliminations.
You can now fill a cell in box 7.
Look at box 4 to determine what can be eliminated from column 1.
Look at box 7 to determine what can be eliminated from row 9.
You can now fill a cell in box 3.

Please reply if you need a more specific hint.

[Finlip]

Can the above puzzle be rated easy?

[scrose]

The Pappocom software rates this puzzle as "hard".

[Finlip]

Oh, Thank you for finding out the raiting for me Mr/Mrs/Miss scrose. Actually the newspaper rated the puzzle easy and it was the first one that really hanged me. I only use a pencil while solving my su dokus.

Yesterday the newspaper had two puzzles one easy and the other difficult. The easy puzzle was again very difficult for me until I found the solution by guesswork. However the solution that was given was different so it meant there were other possible solutions.

Here is the puzzle.

2-- -9- -3-
37- 1-- --4
--8 --3 1--

-3- -8- ---
-2- -1- -9-
9-- -4- -16

--- 8-- 9--
5-- 9-2 -81
-9- -6- -2-

[scrose]

This grid has 7 solutions. Would you mind posting the solution that was given in the newspaper? I'm interested to see which of the 7 solutions was given.

[Finlip]

I only have my solution here. Tomorrow, I will show you both.

[Finlip]

2-- -9- -3-
379 158 264
--8 -23 1-9

-3- -89 --2
-2- 31- -9-
98- 24- 316

--2 8-- 9--
54- 9-2 681
89- -6- -2-

I couldn't get anywhere from here without guessing.

[scrose]

Yes, that's as far as I got, too. I find it suspicious how the starting grid is almost symmetrical, but a few clues are either missing or have been moved around. I wonder if the newspaper made a typesetting error of some sort.

[Finlip]

Okay then please tell me if this other puzzle rated hard published the same day is solvable.

I will ony try it then.

84..15....
5....346.
.........
3......9.
.6.5.2.8.
........2
.........
.578....4
....9..25

[scrose]

Your row 1 has four cells filled and six cells empty, for a total of ten cells; please confirm this row. Also, please double-check if row 6 has only one cell filled.

[Finlip]

In the first row, I added an extra dot in the end. I'm sorry for that. And yes, row six has only one cell given. I haven't been able to fill any more than three cells so far. This may be my first failure to solve a su doku puzzle.

214796835
379158264
658423179
731689542
426315798
985247316
162874953
547932681
893561427

This was the solution given in the newspaper.

[simes]

Code: Select all

84..15...
5....346.
.........
3......9.
.6.5.2.8.
........2
.........
.578....4
....9..25

has 1345 solutions.