Questions tagged [sudoku]

A Sudoku is a puzzle consisting of a grid to be filled with symbols, such that each constraining unit contains each symbol exactly once. The typical example is a 9x9 square to be filled with the numbers 1 to 9, where the constraining units are rows, columns, and 3x3 blocks.

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2
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2answers
232 views

Magical Knight Moves with Effortless Ease in his Magical Kingdom

Magical Knight knows every Square of his Magical Kingdom. In many respects, he is like any other knight...Literary,Prime, Normal(makes same allowed chess moves). He is people Knight . As he traverses ...
2
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1answer
163 views

Help with Sudoku

i recently was playing sudoku on my iPad. As i was stuck on the puzzle i tipped on "Tip" to receive a hint on how i can solve this sudoku (I am still learning the game) - so please don't judge me for ...
2
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1answer
162 views

What can be the next move without guessing in this almost solved Sudoku puzzle?

I am currently stuck at this puzzle where I can't think of the next move without guessing it. I was surprised to be in this situation after solving ~70-80% of the puzzle. I thought for all possible ...
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1answer
114 views

Sudoku board position hint

As the title says, I'd like a hint (and an explanation why it is so) for the puzzle position in the attached image. I think I'm missing something really obvious but I can't figure it out. Again ...
2
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1answer
93 views

Next move for Sudoku puzzle

I am currently stuck at this point in the below Sudoku puzzle. What is my next move and why? Thanks!
2
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1answer
133 views

Setka Puzzle - Complete grid using clues and sudoku-style logic; Tom Hanks

Theme: Tom Hanks This is a Setka puzzle; you can find more (along with a more detailed explanation of the rules) at our website, linked from our profile. How to play Setka, the short version: ...
2
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1answer
1k views

Hexagon (Sudoku-like puzzle)

This is the hexagon with digits to each row and diagonal which follow the rule : If the row and diagonal contains 5 triangles, it must contains all of the digits from 1 to 5. If the row and diagonal ...
2
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1answer
686 views

Sudoku solving strategy

I started solving the puzzle below and I got stuck at this point. I don't know how to continue solving this puzzle except using try and error. Does anyone know of a strategy to solve it?
2
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0answers
135 views

Minimum number of clues required for a 16 x 16 Sudoku

It is well-known that the minimum number of clues that completely specify a 9 x 9 Sudoku is 17. What is the minimum number of clues required for a 16 x 16 Sudoku whose cells contain one of the ...
2
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0answers
160 views

Most objective online linkable sudoku grader?

A Sudoku's difficulty level is often the first thing readers notice about a puzzle. For questions and answers showing a puzzle it would be nice to have a relatively objective linkable tester. I've ...
2
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0answers
334 views

Mastering Sudoku? [duplicate]

I have been solving sudoku for years but this one is the hardest of all that I have ever completed. It took me 2 weeks to complete it. Here it is TRY AND SOLVE:
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2answers
192 views

How do I proceed with this Sudoku puzzle?

Pairing elimination is done. What's next?
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4answers
276 views

What technique should be used to continue with this sudoku

I searched for x wing and the bone. Im thinking colors but not sure.
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3answers
209 views

Can someone solve this sudoku without trial and error? Please explain

Stuck in this sudoku. If anyone can solve this then please share the method.
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1answer
360 views

How can I solve this Sudoku without guessing?

I am fairly new to Sudoku and have hit a brick wall with this one. My colleague said it can only be solved with a guess and seeing how far you go. However, I agree with many on this site and you ...
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2answers
219 views

Sudoku puzzle - where to go next?

Above is a link to a half-solved sudoku puzzle. I tried to fully solve it but just cant figure out what to do now. Source: Sudoku-Branium studios It is an app on google playstore.
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2answers
230 views

Sudoko-net pseudo-solvable with minimum blocks

A sudoku net is defined here. A sudoku net is defined as 'pseudo-solvable' if we can deduce at least two valid 'not unique' solutions . friendly sudoko is defined here What is the sudoku ...
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1answer
6k views

Check sudoku solvability

With a blank grid, I put and number (1-9) any cell, the Sudoku has n solutions. I continue filling any blank cells with numbers that satisfy the constraints, so the Sudoku still has many solutions, ...
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2answers
101 views

How do I go ahead in this?

Got this from daily challenge of sudoku app.
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1answer
316 views

Generate a sudoku puzzle with minimum number of entries that has exactly $k$ solutions

Is there an algorithm to generate a sudoku puzzle having the minimum number of entries that has exactly $k>1$ solutions? What is this minimum number of entries, as a function of $k$? Given that ...
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0answers
48 views

Is it faster to cross reference chains from 2 cells when trying to solve 16*16 sudoku grids

Hi there I'm trying to see if I can solve 16*16 grid Sudoku problems. Does anyone know if its more efficient to use advanced Hodoku techniques or simply with basic rules to cross reference forced ...
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3answers
188 views

Sudoku Move Marked Wrong, Seems Legal: Software Bug? [duplicate]

The included screenshot shows an attempted Sudoku move. The computer is marking it incorrect. There is no other 7 in the row, column, or 3x3 cell. What gives?
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1answer
622 views

Help solve sudoku

I did solve this sudoku in 24 minutes, but I had to guess from this part out. I'm using a website to display this sudoku a lot neater than the original site. I can solve plenty of sudokus, but the ...
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2answers
2k views

Arrange to get sum of 450 when it is added row wise and column wise

I just came across a maths puzzle,where i should get the sum of 9 numbers(multiples of 10) to be 450 both horizontally and vertically in a 9x9 matrix. Picture attached for reference:
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1answer
89 views

What should be my next valid move?

That's the stage I'm now. I am looking at G block (one in left down corner) 4,5 value. I couldn't decide if it should be 4 or 5. How do I decide? And, am I looking at the right place? Any alternate ...
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2answers
283 views

Stuck on this Sudoku puzzle. Please Explain the logic

I have completed this puzzle with the help of hints from the app. But I am not able to figure out the logic. I normally proceed by placing sure (unambiguous) digits first. Then repeat. But here I am ...
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1answer
214 views

Minimum number of clues for Sudoku to have an unique solution? [duplicate]

I already know that 17 clues are a minimum for a Sudoku to have a solution, but I don't consider a Sudoku to be a real Sudoku while having more than one solution.
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1answer
113 views

Stuck with sudoku

Stuck with this for long time now, applied all the techniques i can think of Blank: All possibilities: missed 6 as possibility in R8C5 Verified that this has unique solution
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0answers
101 views

The hardest one I believe [duplicate]

If you are really smart solve this Sudoku within a day BEST OF LUCK
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3answers
2k views

Can a 9x9 sudoku with sum 45 and square sum 285 of (rows, columns, 3x3) not be valid? [closed]

I have created a program that checks if a Sudoku solution is correct. It tries to do so by checking the following: Rows, columns, 3x3 grids if the sum of the numbers is 45 $(1+2+3...+9=45)$ Rows, ...
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3answers
3k views

Why must a sudoku have a unique solution [closed]

Why must a sudoku have a unique solution. In my books I don't guarantee it. But I am sure there are not many which don't. I doubt if one in a thousand dont have. And even if they don't its only a ...
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2answers
271 views

SUDOKU What next? [closed]

I have solved up to this point. How do I proceed without guessing?
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2answers
237 views

How does one make a program to provide all the 'possible' numbers in an empty cell

To be able to solve a sudoku one usually has to first work out all the 'possible' numbers in an empty cell. How can one make a program to do this? In this case 'possible numbers' are ones which have ...
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2answers
254 views

Amazing sudoku who can find hot numbers

Sudoku X Place the numbers 1-6 once in every row, column, diagonal, and 3x2 block. The diagonals form an X and are highlighted. Puzzle Text of puzzle ----------------- | . . . | 5 . . | | . . . | ...
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1answer
263 views

Traps on Sudoku grids [closed]

Let's have a 9x9 Sudoku grid. Where the dots are shown above, you are allowed to put the numbers 2, 4, 6, 8. Each of these appears seven, seven, seven, and six times. It does not matter which number ...
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2answers
219 views

What is wrong with this Sudoku Game?

Before you, you have a game. There's something wrong with this game. Can you figure out what it is? ...
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2answers
190 views

Numberless Sudoku with Just a Letter and Symbol Combination

A Standard 9x9 Sudoku uses the digits 1 to 9. You are only allowed to use a single letter(say T) and a symbol of your choice to represent the digits 1 to 9. Rules should be well defined and the ...
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2answers
1k views

Sudoku puzzle #1

Please solve the following sudoku puzzle (from Wikipedia):

1 2 3 4
5