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Anti Chess and Forbidden Pairs puzzles
http://www.rcbroughton.co.uk/sudoku/forum/viewtopic.php?f=13&t=766
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Author:  tarek [ Thu May 20, 2010 7:06 am ]
Post subject:  Anti Chess and Forbidden Pairs puzzles

This Puzzle variant which can be described as an anti-king (a cell can't be the same as any of its direct 8 neighbours) with a top-down Rt-Left wrap ... is an easy one

The wrapping will make each cell have 8 cell neighbours including the edge & corner cells.
example of such a grid with cell r1c1 & its 8 neighbours:
Image

Here is the puzzle which I'm providing the solution later
Image
Code:
8..1.2..................5...1.7.........5....3....4...2.8..................9.8...
 8 . . | 1 . 2 | . . . 
 . . . | . . . | . . . 
 . . . | . . . | 5 . . 
------+-------+------
 . 1 . | 7 . . | . . . 
 . . . | . 5 . | . . . 
 3 . . | . . 4 | . . . 
------+-------+------
 2 . 8 | . . . | . . . 
 . . . | . . . | . . . 
 . . . | 9 . 8 | . . .

Author:  HATMAN [ Mon May 24, 2010 8:04 am ]
Post subject:  Re: Touchless Wrapper

Another nice paper solvable - Although I did have problems with the wrap by my third pint of Guiness.

Author:  tarek [ Mon May 24, 2010 6:41 pm ]
Post subject:  Re: Touchless Wrapper

HATMAN wrote:
I did have problems with the wrap by my third pint of Guiness.
:lol:

tarek

Author:  tarek [ Fri Jan 18, 2019 8:32 am ]
Post subject:  2 Forbidden Pairs puzzles

Code:
Sudoku No8kN8  (No 8 Knight)
Easy
Cells that are a Knight move apart Shouldn't give you 8 through simple arithmetic operations

......................1.....12..7................3..9.7.....241...8..............
+-------+-------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | . 1 . | . . . |
+-------+-------+-------+
| . 1 2 | . . 7 | . . . |
| . . . | . . . | . . . |
| . . . | . 3 . | . 9 . |
+-------+-------+-------+
| 7 . . | . . . | 2 4 1 |
| . . . | 8 . . | . . . |
| . . . | . . . | . . . |
+-------+-------+-------+

Hidden Text:
Image

Hidden Text:
Code:
Hint:
1 * 8 = 8
1 + 7 = 8
8 / 1 = 8
9 - 1 = 8
2 * 4 = 8
2 + 6 = 8
3 + 5 = 8
4 + 4 = 8

Only + - * / are basic arithmatic operations so 2 ^ 3 = 8 is not included



Code:
Latin square No Tennis:
Easy
Latin square Puzzle, adjacent cells combination can't be an Australian Tennis Open final set result score
.234.........8.....8.....1............9..13............6.....2.....3......42.7.9.
. 2 3 4 . . . . .
. . . . 8 . . . .
. 8 . . . . . 1 .
. . . . . . . . .
. . 9 . . 1 3 . .
. . . . . . . . .
. 6 . . . . . 2 .
. . . . 3 . . . .
. . 4 2 . 7 . 9 .

Hidden Text:
Image

Hidden Text:
Code:
Hint:
Don't forget 7-5 7-6 8-6 9-7

Author:  tarek [ Mon Jan 21, 2019 8:27 pm ]
Post subject:  Sudoku No Squares

Sudoku No Squares (Easy)
Sudoku puzzle where adjacent cell combinations can't form a 2-digit square number
Code:
Sudoku No Squares (Easy)
Sudoku puzzle: Adjacent cells combinations can't form a 2-digit square number
...4..8......8....8................8.9.....7.4................1....6......3..5...
+-------+-------+-------+
| . . . | 4 . . | 8 . . |
| . . . | . 8 . | . . . |
| 8 . . | . . . | . . . |
+-------+-------+-------+
| . . . | . . . | . . 8 |
| . 9 . | . . . | . 7 . |
| 4 . . | . . . | . . . |
+-------+-------+-------+
| . . . | . . . | . . 1 |
| . . . | . 6 . | . . . |
| . . 3 | . . 5 | . . . |
+-------+-------+-------+

Image
Hidden Text:
Hint:
64 is a 2-digit square number, so a cell that has 4 can't be adjacent to a cell that has 6

Author:  azpaull [ Wed Jan 23, 2019 12:03 am ]
Post subject:  Re: Touchless Wrapper

HATMAN wrote:
Another nice paper solvable - Although I did have problems with the wrap by my third pint of Guiness.

Wait! Does that mean you finished it in 3 pints, or did you have to resume the following a.m.? I think we may have stumbled on a new rating system! ('Course, it may be a "6D" system with all of the added factors.)

I just printed it out, and am going to have to teetotal to have any chance at it! :lol:

Author:  tarek [ Thu Jan 24, 2019 2:24 pm ]
Post subject:  Re: Touchless Wrapper

azpaull wrote:
HATMAN wrote:
I just printed it out, and am going to have to teetotal to have any chance at it! :lol:
Some of the puzzles in this variant I've posted can cause vertigo & torticollis so approach with caution :lol:

Author:  tarek [ Thu Jan 24, 2019 2:25 pm ]
Post subject:  Re: No8kN8 & No tennis solutions

Hidden Text:
Code:
No8kN8
167385924284769315953214768312947586849652137576138492738596241495821673621473859
+-------+-------+-------+
| 1 6 7 | 3 8 5 | 9 2 4 |
| 2 8 4 | 7 6 9 | 3 1 5 |
| 9 5 3 | 2 1 4 | 7 6 8 |
+-------+-------+-------+
| 3 1 2 | 9 4 7 | 5 8 6 |
| 8 4 9 | 6 5 2 | 1 3 7 |
| 5 7 6 | 1 3 8 | 4 9 2 |
+-------+-------+-------+
| 7 3 8 | 5 9 6 | 2 4 1 |
| 4 9 5 | 8 2 1 | 6 7 3 |
| 6 2 1 | 4 7 3 | 8 5 9 |
+-------+-------+-------+
1 * 8 = 8
1 + 7 = 8
8 / 1 = 8
9 - 1 = 8
2 * 4 = 8
2 + 6 = 8
3 + 5 = 8
4 + 4 = 8
FP Knight (1,7)(1,8)(1,9)(2,4)(2,6)(3,5)(4,4)

LS No tennis
123478965372189654487396512718965243249651378896524137965843721651732489534217896
1 2 3 4 7 8 9 6 5
3 7 2 1 8 9 6 5 4
4 8 7 3 9 6 5 1 2
7 1 8 9 6 5 2 4 3
2 4 9 6 5 1 3 7 8
8 9 6 5 2 4 1 3 7
9 6 5 8 4 3 7 2 1
6 5 1 7 3 2 4 8 9
5 3 4 2 1 7 8 9 6
FP Adjacent (1,6)(2,6)(3,6)(4,6)(5,7)(6,7)(6,8)(7,9)

Author:  tarek [ Sun Jan 27, 2019 3:28 pm ]
Post subject:  sudoku No Squares solution

Sudoku No Squares Solution

Hidden Text:
Code:
931426857624587319875931426317659248596842173482713965268374591159268734743195682
+-------+-------+-------+
| 9 3 1 | 4 2 6 | 8 5 7 |
| 6 2 4 | 5 8 7 | 3 1 9 |
| 8 7 5 | 9 3 1 | 4 2 6 |
+-------+-------+-------+
| 3 1 7 | 6 5 9 | 2 4 8 |
| 5 9 6 | 8 4 2 | 1 7 3 |
| 4 8 2 | 7 1 3 | 9 6 5 |
+-------+-------+-------+
| 2 6 8 | 3 7 4 | 5 9 1 |
| 1 5 9 | 2 6 8 | 7 3 4 |
| 7 4 3 | 1 9 5 | 6 8 2 |
+-------+-------+-------+
FP (1,6)(1,8)(2,5)(3,6)(4,6)(4,9)

Author:  Andrew [ Fri Aug 09, 2019 4:22 am ]
Post subject:  Re: Anti Chess and Forbidden Pairs puzzles

I only came across these nice puzzles a few months ago. A typical variety for this forum which has so many different types of sudokus.

I initially got stuck on the Anti-King Wraparound puzzle and my late evening glass of single malt (whisky) didn't help much. Then I came back to it today, early evening, and managed to spot the anti-Kings that I'd been missing before (I do them manually on my Excel worksheet), the hardest one to spot being the naked pair {67} in R2C9 and R3C1, which eliminated 6,7 from R2C23.

tarek doesn't seem to have posted the solution to this puzzle.
Solution:
8 5 6 1 3 2 4 7 9
1 4 3 5 9 7 8 2 6
7 2 9 8 4 6 5 1 3
6 1 4 7 2 9 3 8 5
9 8 2 3 5 1 7 6 4
3 7 5 6 8 4 2 9 1
2 9 8 4 1 5 6 3 7
5 6 1 2 7 3 9 4 8
4 3 7 9 6 8 1 5 2

The No Squares and No Tennis puzzles were both easy.

Having originally got stuck on the No 8 Knight puzzle; I've now had another look at it and realised I'd missed a knight move, then I needed a short forcing chain to force one placement which allowed me to finish it, so it felt a bit harder than Easy.

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