Logical puzzles

[Admin]

One way to waste brainpower is on logical puzzles like sudoku. It might however increase your mental abilities assuming you are not cheating too much by taking notices while solving an easy puzzle.

Very basic

Basic

Easy
sudokuwiki.org/sudoku.htm?bd=000000000406000201902000374000105000600020000010043000300000080000000459209000600
sudokuwiki.org/sudoku.htm?bd=001006050200080034080300200310000008006000040000000100700250000002704000104009000

Medium

1 to 9 in every box and row that can contain 9 numbers (vertical, horizontal, market diagonal rows).

hard

This is a standard sudoku where you just need to have 1 to 9 in each big box, each vertical row, each horizontal row.

The following hard sudoku also has to have 1 to 9 in the green boxes:

sudokuwiki.org/windoku.htm?bd=000054000000000010006000700690008020300000008080000090005000400060000030000000000

Extreme I

Some of the following puzzle may also be difficult enough to be placed in the extreme category:

https://www.conceptispuzzles.com/index.aspx?uri=info/article/424

 

[Admin]

Solving sudoku
Even supposedly hard sudoku puzzles can typically be solved relying on the basics plus trial and error, it's just a matter of how much time you have to waste. If it's too many steps ahead for you to memorise you can just make another copy of it and manually input the right solution.

One hard suduko can be converted into multiple easier versions to solve where at least one of these versions will have a solution.

Advances strategies such as alternating interference chains can be useful to know but it's not really necessary.

 

[Admin]

Cubes
These puzzles are generally not super-difficult once you know or have figured out algorithms, in the case of the standard 3x3x3 you do not even need to know much if anything in terms of algorithms to solve it, you can grind until you get lucky enough to solve it.

One of the more difficult puzzles is the crazy 4x4x4 III

 

[Admin]

Extreme II
These puzzles/problems were difficult to solve even with the help of computers but eventually a solution was found.

 

[Admin]

Extreme III
These puzzles are still unsolved despite efforts to crack them, still no major effort has been made to solve them.

This can be being the first to crack come closed sourced software (such as horizon: zero dawn)

 

[Admin]

Extreme IIII
Despite significant effort the puzzle remain unsolved.

One example is trying to unify the laws of physics, people have tried this for decades having access to very powerful computers but despite significant world-wide effort we are still not aware of any decent candidate for a solution.

https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_mathematics

 

[Creamer]

solve to unveil a delicious walkthrough
23 1 20 5 18 13 5 12 15 14 + 2 21 12 7 1 18 9 1 14 3 8 5 5 19 5