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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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 ...
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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?...
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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 ...
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A new puzzle - Sudoku X V
If someone is able to find the solution... I found 2,3,8 on line 5, column 3-4-5, but after that I am blocked, it looks too difficult for me.
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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:
...
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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 ...
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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:
...
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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
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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:
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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 ...
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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 ⋅ ...
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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 \...
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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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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 ...
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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 ...
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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 ...
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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 ...
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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) ...
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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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Sudoku - can’t get any further
What technique am I missing here? I have try all the usual naked pairs etc.
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Another new puzzle type needs a name
For an example of how this type of puzzle works, see here...
I believe I have invented another new type of puzzle...
What is its name?
Colour-blind-friendly version available here.
Begin by ...
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What is the technique I should use now to go ahead?
This is a partially filled sudoku from the Sudoku Expert app.
I thought I learnt all tricks and techniques. But clearly there is something I don't know about.
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Help with a sudoku puzzle
I would really appreciate some help because I spent more than hours finding another number. It is supposed to be a very hard one but I started well and according to the key, my numbers are correct. Do ...
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How much information can we get from a thermometer?
A fairly common Sudoku variant is so called "Thermometer" Sudoku. In this variant arrows with a rounded end (which look like a thermometer) are added to the grid, with the rule that the numbers on ...
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Sudoku, unclear next logical step?
Solved up until here, I took the sudoku through an online solver and it seemed to use a guess and check strategy? Is that the only way of getting the solution or am I missing something?
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All That Remains Sudoku
. 2 . | . 7 . | . . 9
. 9 8 | . . . | . . .
3 . . | 9 . . | . . .
---------+---------+--------
2 . 7 | . . . | . . .
. 1 5 | 7 . . | . . .
. . . | 1 5 8 | . ...
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Whirlwind of the Square Sudoku Table
. . . | . . . | . . .
6 . . | . . 1 | . 2 .
. . . | . . . | . . .
---------+---------+--------
. . 7 | . . . | . . .
. . . | . . . | . . .
. . . | . . . | . ...
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This new puzzle type needs a name
I believe I have invented a new type of puzzle...
What is its name?
Colour-blind-friendly version available here.
Begin by solving the 16x16 sudoku; each of the digits 1-16 must appear exactly ...
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Queens of the Square Sudoku Table
. 6 . | 8 . 3 | . 7 .
. . 1 | . . . | . 6 9
7 . . | . . . | . . 5
---------+---------+--------
. . . | 9 . . | . 1 .
. . . | . . . | . . 4
. . 5 | . 1 . | . ...
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What technique I should use now? [closed]
I am stuck here. I don't want solution for this, I just want to know the name of technique which will be used here to go ahead.
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Knights of the Square Sudoku Table
8 . . | . . . | . . 6
. . 4 | . . . | . . .
. . . | . . . | 9 1 .
---------+---------+--------
. . . | . 2 . | . . .
. . 9 | 3 . . | . . .
. . . | . . . | . ...
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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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Another Colombian Sudoku
Solve the Sudoku on the left, where the usual rules apply.
The dots outside the board on the right indicate how many cells in the corresponding column or row of that board contain precisely the same ...
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What patterns could be applied in order to solve a Sudoku?
Related to this Q&A. I am looking for a pattern that could be applied in order to solve this Sudoku.
The current patterns that I apply:
Ensure that every digit appears once in every block
Ensure ...
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Can you help me with a logic to solve this puzzle?
I know the concept of pairing and removed pairs but what other concepts should I use to solve this?
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Excluding number in a sudoku scheme
I have the following scheme:
Please look at the lower left subgrid. The 8 may go in R7C1 or R9C1.
If I put the 8 in R7C1 I'd have a 4 in R9C7 and a 5 in R8C7
If I put the 8 in R9C1 I'd have the ...
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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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What am I missing in this Sudoku?
I think I am missing something in the instance below, since I could solve it only with a long-winded chain of deductions starting with the assumption that (coordinates are (row,column)):
and ...
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Sudokus and combinatorics
Considering your suggestions, I have redrawn the 12 X 12 Sudoku so that the twelve rectangles are now visible. The question remains the same:
Can someone construct a 12 X 12 Sudoku with the following ...
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What next step can I take in solving this sudoku?
There are lots of pairs and I don't want to assume any values.
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Minimum amount of clues for a 16x16 sudoku
I know that 17 is the minimum for a standard 9x9 (3x3 squares), but what about a 16x16 (4x4 squares) sudoku?
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Sandwich Sudoku: First 12 digits of pi
Sandwich Sudoku, or "Between 1 and 9 Sudoku", is a variant of Sudoku. A YouTube channel introduced this variation.
Rules:
Standard Sudoku rules. Place numbers from 1 to 9 in every row, column, ...
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What is the best way to solve this 6x6 sudoku? [closed]
I eventually used a trial and error method to solve it:
Assume B1 = 2
C2 and F1 = 4
C3 = 2
F3 = 6
There are no candidates left for A3
This let me set B1 = 4 and hence solve the puzzle. But is there ...
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Was "Crook's algorithm" for Sudoku really only developed in the 21st century?
The following algorithm for simplifying (and very often completely solving) Sudoku puzzles:
Label each cell with the set of all possible values it could take.
Pick a row/column/block and for a value ...
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How can I solve this sudoku?
I've almost finished this hard sudoku, but I cannot finish it without guessing or making multiple blind steps to see if I'm wrong or not. Even https://www.sudoku-solutions.com/ gives up and says "...
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Is there a Sudoku answer that has only a single minimal clue set?
User Abigail comments on the titling of "Do sudoku answers always have a single minimal clue set?"
:
I'd be surprised if there were a Sudoku which doesn't have at least 2 disjoint clue-sets.
Well ...
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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 ...
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Maximum number of disjoint clue-sets that determine the same Sudoku solution?
"Do sudoku answers always have a single minimal clue set?" No. Solved Sudoku puzzles may have more than one set of disjoint clue-sets. And those clue-sets can vary in difficulty, so one might be ...
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