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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19
votes
1answer
203 views

Arithmetic Progression Sudoku

In this puzzle, each square must contain a positive integer. All rows, columns and boxes must contain an arithmetic progression of length 9. Good luck!
21
votes
1answer
319 views

Square Number Sudoku

Solve this diabolic Square Number Sudoku. Normal Sudoku Apply. Additionally, there are some rectangled area, in each area should be read as 1 number. The numbers must be SQUARE NUMBERS. There are: 1 1-...
21
votes
1answer
309 views

Monument Valley Sudoku

Another Sudoku monstrosity from the brains of Yours Truly. No rules are given, part of the challenge is trying to work out what the rules are :)
24
votes
1answer
292 views

George Orwell Sudoku

Here is a puzzle I created today. The title is "George Orwell Sudoku" Normal Sudoku rules apply. In every coloured group of three cells the middle digit must equal the sum of the other two ...
26
votes
2answers
575 views

A Minesweeper Sudoku

My brother created this puzzle, and he wanted me to post this here. Each 3x3 box contains three mines (those squares also have numbers in them). There are no mines in boxes containing a 1, 2, or 3. ...
1
vote
3answers
206 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.
7
votes
1answer
728 views

How can this puzzle be solved without guessing?

This puzzle was given to my 8 year old from the school. My child was struggling, so I gave it a bash, but was unable. I do sudoku regularly so know most methods of solving. I gave it to my husband and ...
3
votes
2answers
109 views

stucked really bad with sudoku puzzle

Stuck with this for long time now, I have tried all the techniques yhat I know
4
votes
1answer
156 views

How to test a sudoku solver?

I have created a standard sudoku solver using my own algorithm. It relies on a continuous scanning with occasional tuple/pair searching. I am looking forward to test if this works properly. I have ...
0
votes
1answer
112 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
5
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2answers
573 views

Multiplicative sudoku (don’t use computers please)

If I place all the numbers from 1 to 9 in a 3x3 grid and I add the products of each row and column, then what is the minimal and the maximal sum? For example, the sum is 450 on the picture above
3
votes
1answer
244 views

How many unique “miracle sudokus” are there?

The following "Miracle Sudoku" puzzle contains only two starting numbers, plus some additional rules that end up revealing the whole board: https://www.youtube.com/watch?v=yKf9aUIxdb4 (or Sudoku ...
23
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2answers
4k views

What if I told you that guessing in Sudoku is very bad and might give you a bad karma?

Yesterday, I tried to solve a regular Sudoku puzzle. Of course, the Sudoku puzzle had a unique solution. But, I was feeling a little lazy, so, rather than solve the puzzle properly, I made guesses! At ...
4
votes
1answer
462 views

Sudoku: Stuck, Need hint to move forward

I have applied the techniques I know to eliminate possible candidates. I'm stuck at this stage now, any hints to move forward are appreciated. I found this puzzle in Microsoft sudoku Android app.
2
votes
2answers
238 views

Next move for Sudoku puzzle and why [closed]

I am currently stuck at this point in the below Sudoku puzzle. I have tried to apply various tricks such as XY wing, swordfish etc. but the preconditions are not fulfilled for any number. What is my ...
9
votes
5answers
2k views

Sudoku medium difficulty help

I keep getting stuck on the NY Times Sudoku medium difficulty puzzles. I go through one number at a time and narrow down large box where that number can only be in two spaces. When I finish the nines ...
13
votes
2answers
729 views

Sudoku variation: Using various chess moves, solve the grid from just two numbers

I've been watching a youtube channel hosted by puzzlers and attempting the sudoku variation they post each day. Today's I found particularly interesting and while sharing it around it proved quite the ...
4
votes
1answer
127 views

Smudged Sudoku - help me solve it!

One late evening I was making my sudoku. I finally finished until water spilled all over the middle-right block. The only thing I remember is the numbers present in the block (but not their position):...
9
votes
2answers
949 views

Sudoku Help: Hard

I am unable to finish this Sudoku. All numbers are verified by the app. I'm sure there must be a way to solve this without guessing. Even an online tool couldn't tell me a next number.
19
votes
2answers
965 views

Tic tac toe - Sudoku: A variation in which the centre box defines the layout of the other boxes

I stumbled across this interesting variation of Sudoku the other day and thought I'd give it a try, it has however baffled me and I've been unable to progress past the very early stages. The puzzle ...
2
votes
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 ...
9
votes
1answer
187 views

Puzzle of the day - three in one Sudoku?

A three in one sudoku. Have fun
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!
17
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4answers
807 views

Knights in a Complete Sudoku Board

In a complete Sudoku board, at most how many chess knights would it be possible to place on its cells with a 1 inside, so that each knight can walk in order (1, 2, 3, ..., 9) through cells numbered up ...
1
vote
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 ...
8
votes
1answer
150 views

Sliced sudoku: rearrange the tiles and then solve it

Rearrange the tiles without rotating nor flipping them to form a $9 \times 9$ sudoku. Then solve the sudoku according to the standard rules. Credits: the sudoku is one of the twelve schemas freely ...
11
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2answers
1k views

Not to waste a perfectly good puzzle

I formulated this puzzle as part of a project I'm working on. However, it turned out that it was, uh, a bit too difficult to include for the audience we're aiming it at - it took someone over 40 ...
2
votes
2answers
223 views

Logical Sudoku - How to tell when fully deducted?

I'm working a program that should generate bad ass sudoku puzzles. Recently I noticed there's a thing called "logical sudoku", which means it can be logical-deducted all the way to solution. The ...
7
votes
2answers
229 views

Puzzle of the day, Frame Sudoku

The rules are the same as the classic Sudoku, but the numbers outside the grid are the sum of the first three digits placed closest to that row or column
19
votes
4answers
3k views

After here should I guess or is there a logic solution on Sudoku?

From this point is it necessary to guess or is it possible to find a logic solution?
21
votes
2answers
919 views

Complaint at the PSE lounge

While walking through the PSE lounge, I noticed a piece of paper on one of the tables. Picking it up, I saw several things. The first, was a couple of sentences at the top: I love this place! But ...
8
votes
2answers
323 views

Q: Henry Goldman's Square of Digits

Jaap Scherphuis introduced The Arithmachinist by Henry Goldman in his post Goldman's Transformation Puzzle. In the book I found a curious figure on p.52. I wonder what it means. Could you let me know?...
15
votes
1answer
403 views

Kropki Sudoku – Sudoku based on the relation between neighbouring numbers

This puzzle is named Kropki Sudoku. The classic sudoku rules apply: Place numbers on the grid below such that each row, column and 3×3 box contain the numbers 1 to 9. A white dot indicates that the ...
2
votes
1answer
132 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: ...
33
votes
1answer
3k views

MASTERING Sudoku

Fill the grid with letters M, A, S, T, E, R, I, N and G. Standard Sudoku rules apply. Additionally, the words on the right-hand side must appear in the given orientation (across/down). Each word ...
3
votes
1answer
67 views

Setka - Complete grid using clues and sudoku-style logic; Theme - Fear Itself

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. Theme: Fear Itself How to play Setka, the short version: ...
5
votes
1answer
155 views

Against the Grain, Salt to the Sea: Sudoku

Against the Grain, Grain of Salt, Salt to the Sea, Sea...badge? What Badge? Of course, guessing is not fun, right? Anyway, congratulations to anyone who get this! :D
17
votes
2answers
914 views

Why would I need a Lamborghini Rebenton?

The proper word to use as the ninth symbol is in Berlin (3) Daily Hint 1: Daily Hint 2: Daily Hint 3: Daily Hint 4: Daily Hint 5:
16
votes
2answers
633 views

This new puzzle type needs a name {5}

I believe I have invented a new type of puzzle... What is its name? Colour-blind-friendly version available here. Begin by solving the 9x9 sudoku; each of the 9 symbols ...
5
votes
1answer
184 views

Just Another Sudoku for PSE

Crafted with love for PSE, <3
12
votes
2answers
329 views

Specialist sudoku

I know y'all want to be generalists or something, but here's a little sudoku for (geography) specialists. Enjoy. ABRAU ⋅ AGANTON ⋅ AKUSEKIJIMA ⋅ ALICE HOLT ⋅ ALTENBURG-NOBITZ ⋅ ANJEDIVA ⋅ APULIA ⋅ ...
19
votes
1answer
961 views

Your Task Is to Create the World's Hardest Irregular Sudoku!

Ahem, let's formalize your task... 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 regular Sudoku is a $9 \...
1
vote
2answers
101 views

How do I go ahead in this?

Got this from daily challenge of sudoku app.
-3
votes
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 ...
11
votes
2answers
477 views

Setka - Complete grid using clues and sudoku-style logic; Theme - Halftime

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: Answer each clue using ...
12
votes
1answer
841 views

This new puzzle type needs a name {4}

I believe I have invented a new type of puzzle... What is its name? Begin by solving the 16x16 sudoku; each of the digits 1-16 must appear exactly once in each row, column and thick-bordered 4x4 ...
4
votes
2answers
263 views

What is the maximum number of numbers a sudoku can have and have more than one solution?

I was watching this video where he talked about how scientists found the minimum number of numbers a Sudoku can have and still have exactly one solution. This led me to think of the opposite - what is ...
3
votes
1answer
178 views

Can I swap two “yellow” corners on the same side?

The bottom two layers are solved, and the cross has been formed on the bottom layer. I am putting the corners in, ready to orientate them correctly, but I have two corners which need swapping. (The ...
12
votes
2answers
544 views

Compoundoku wants BIG

Rules of Compoundoku: Solve both left and right Sudokus. In addition, the board below them is the Compound Board of both Sudokus. Each number on the Compound Board should tell either: (1) ...
23
votes
2answers
1k views

Introducing: Compoundoku!

Rules of Compoundoku: Solve both left and right Sudokus. In addition, the board below them is the Compound Board of both Sudokus. Each number on the Compound Board should tell either: (1) ...

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