Post the puzzle or solving technique that's causing you trouble and someone will help

I tried in the bottom right between 1 & 9 and would reach an answer, but I was wondering how to do it with purely notes. Please take it slow, I'm new to notes.
Thank you.
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Extreme Sudoku
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Jacky

Posts: 9
Joined: 18 June 2016

98.3751.227...853.35...28.756329.7.87.856392..2978.3568.24576.3..583627.637129485

I see a Unique Rectangle (type 2), followed shortly by a BUG+1.

JasonLion
2017 Supporter

Posts: 642
Joined: 25 October 2007
Location: Silver Spring, MD, USA

I recently mentioned in another thread here that Skyscrapers are quite often found to be the solution to queries we get. It didn't take long for one to come up.

Code: Select all
`*-----------------------------------------------------*| 9    8    46    | 3    7    5     | 1    46   2     || 2    7    146   | 69   14   8     | 5    3    49    || 3    5    146   | 69   14   2     | 8    469  7     ||-----------------+-----------------+-----------------|| 5    6    3     | 2    9    14    | 7    4-1  8     || 7   b14   8     | 5    6    3     | 9    2   a14    || 14   2    9     | 7    8    14    | 3    5    6     ||-----------------+-----------------+-----------------|| 8   c19   2     | 4    5    7     | 6   d19   3     || 14   149  5     | 8    3    6     | 2    7    9-1   || 6    3    7     | 1    2    9     | 4    8    5     |*-----------------------------------------------------*`

There is a Skyscraper in 1's in cells a, b, c and d. At least one one of cell a or d must be 1 so you can remove the 1's from r4c8 and r8c9, solving the puzzle.

If you want further explanation of how Skyscrapers work just ask and I'll explain further, or you can learn about them here.

Leren

Posts: 4110
Joined: 03 June 2012

Skyscraper huh?
Couldn't R6 and R8 in C1, and R5 and R9 in C9 be a "Skyscaper" as well?
Jacky

Posts: 9
Joined: 18 June 2016

Yes, there is a Skyscraper in 1's in r68c1 and r5c8c9 which eliminates the 1 in r5c2 and solves the puzzle.

I see you've got the idea, nicely spotted, Leren
Leren

Posts: 4110
Joined: 03 June 2012