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13 votes
Accepted

Solid border Yin-Yang

ralphmerridew's user avatar
5 votes
Accepted

Colombian Sudoku, Cows and Bulls again…

Completed grid: As usual, we begin by using our given digits to mark cells which match and cells which cannot match. We then: As usual, I forget that the lack of a clue in column 8 actually means ...
Jeremy Dover's user avatar
  • 28.8k
0 votes

Eliminate some numbers so that each of the three rows contains the numbers 1 through 9 each exactly once

...
catpop's user avatar
  • 1
1 vote
Accepted

What is the name of this puzzle type? How to create one? nxn grid where you select n cells with different numbers

The solution is called a transversal in an $n \times n$ array with $n$ symbols (for example, in a Latin square): https://en.wikipedia.org/wiki/Latin_square#Transversals_and_rainbow_matchings For a ...
RobPratt's user avatar
  • 14.4k
3 votes

Fill the triangular grid using the digits 1-9 subject to the constraints provided

Gave it a try in "hard mode", where the two knowledge-ish diagonals (MCCCXCVIII and Fahrenheit) are not used in the solving process. It turns out that it is indeed possible to find the ...
Bubbler's user avatar
  • 16.4k
5 votes

Fill the triangular grid using the digits 1-9 subject to the constraints provided

Solution: Solving Path
Lukas Rotter's user avatar
  • 11.2k
4 votes

Eliminate some numbers so that each of the three rows contains the numbers 1 through 9 each exactly once

Lucenaposition's user avatar
8 votes
Accepted

Eliminate some numbers so that each of the three rows contains the numbers 1 through 9 each exactly once

So the starting combination is ...
Novarg's user avatar
  • 4,057
24 votes
Accepted

Are you radical enough to solve this SURDOKU?

Surd-lution (sorry :P): To start: Now the step by step: 1: 2: 3: 4: 5: 6:
Beastly Gerbil's user avatar
14 votes
Accepted

Fill the grid subject to product, sum and knight move constraints

Bubbler's user avatar
  • 16.4k
4 votes

Fill the grid subject to product, sum and knight move constraints

You can solve the problem via integer linear programming as follows. For $i,j\in\{1,\dots,5\}$ and $k\in\{1,\dots,20\}$, let binary decision variable $x_{ijk}$ indicate whether cell $(i,j)$ takes ...
RobPratt's user avatar
  • 14.4k
7 votes

Fill the grid subject to product, sum and knight move constraints

First find a place for 19: Then for 17: Then for 18: For 11, 12, 13: For 14, 15, 16: Continuing: The completed grid:
Daniel Mathias's user avatar
4 votes
Accepted

A colourful Colombian Sudoku

Surprisingly very tricky! Here's the solution: Step by step: 1 - First steps: 2 - Completed clues: 3 - Cross checking: 4 - First numbers: 5 - It was all yellow: 6 - Contradiction: 7 - Little ...
Beastly Gerbil's user avatar
10 votes
Accepted

Tombs of Ancients

Gladys is visiting Solution Step-by-step
user39583's user avatar
  • 9,103

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