## Robert's puzzles 2020-03-20

Post puzzles for others to solve here.

### Robert's puzzles 2020-03-20

Hi all,
I propose this puzzle that in my TDP classification has a level 2.
Good sudoku and protect yourself from this scourge of coronavirus.
Robert

..2.3...6.5.9.6.4.6..8..2...18...5....7.9...4.65...3.....2..7...8.3.4.2...6.5...3

puzzle: Show

my resolution: Show
My resolution with TDP after 6 singles and a few eliminations by the basic techniques (TB).
1) Crossing of two conjugated tracks. (see diagrams)
P(7r8c5) : 7r8c5-> ... ->2r9c2
P(7r8c1) : 7r8c1->(5r8c4->5r1c8)->(hidden Skyscraper with 9)->(-9)r9c2->2r9c2
=> r2c9=2 => 2 placements and several eliminations with TB.

Code: Select all
`7r8c5->6r8c7->9r1c7---->7r1c2->7r9c1->2r9c2     \                /       ->4r4c5->4r1c4          ----------------------------        /                              \       /                ->9r8c3-------->\      /               /                  \7r8c1->(5r8c4->5r1c8)-                    ->2r9c2      \               \                  /       \                ->9r8c7->9r1c2->/        \                              /          ----------------------------`

2) Use of 3 successive anti-tracks
P'(5r5c4) : -5r5c4->5r5c6->5r3c9->5r8c1->7r8c5->4r4c5->4r1c4 => -5r1c4 => 2 placements and 2 eliminations
P'(9r8c3) : -9r8c3->1r8c3->7r9c1->7r8c5->6r8c7 => -9r8c7 => r1c8=9
P'(7r9c1) : -7r9c1->7r9c4->16r8c57->9r8c3->9r3c2->7r1c2->5r1c6->5r3c9->5r8c1 => -7r8c1, stte.
Robert
Last edited by Mauriès Robert on Fri Mar 20, 2020 5:22 pm, edited 1 time in total.
Mauriès Robert

Posts: 321
Joined: 07 November 2019
Location: France

### Re: Robert's puzzles 2020-03-20

Solved in four steps. The last kraken could be replaced by a sequence of AIC's
Code: Select all
` +----------------------+-----------------------+-----------------------+ |  178   D479   2      | a147-5  3      157    |  189  h15789   6      |  |  138-7  5     13     |  9      2      6      |  18    4       178    |  |  6     D479  D149    |  8    Cb147    157    |  2     3      g1579   |  +----------------------+-----------------------+-----------------------+ |  49     1     8      |  467  Cc47     3      |  5     679     2      |  |  23     23    7      |  156    9      158    |  168   168     4      |  |  49     6     5      |  147    1478   2      |  3     1789    1789   |  +----------------------+-----------------------+-----------------------+ |  135    349   1349   |  2      168    189    |  7     15689   1589   |  |Ae157    8     19     |  3    Bd167    4      |  169   2      f159    |  |  127    279   6      |  17     5      1789   |  4     189     3      |  +----------------------+-----------------------+-----------------------+`

1. (4)r1c4 = r3c5 - (4=7)r4c5 - r8c5 = (7-5)r8c1 = r8c9 - r3c9 = (5)r1c8 => -5 r1c4; 2 placements & basics
2. (7)r8c1 = r8c5 - (7=41)r34c5 - (1=497)b1p289 => -7 r2c1; 1 placement & basics

Code: Select all
` +-----------------------+----------------------+-----------------------+ |  178    A479*  2      |  147   3      157    | A189* w1589    6      |  |  138     5     13     |  9     2      6      |  18    4       7      |  |  6       479   149    |  8    f147    157    |  2     3      x159    |  +-----------------------+----------------------+-----------------------+ |  49      1     8      |  6    f47     3      |  5     79      2      |  |  23      23    7      |  5     9      18     |  168   168     4      |  |  49      6     5      |  147  f1478   2      |  3     1789   e189    |  +-----------------------+----------------------+-----------------------+ |  135     34-9  134-9  |  2     168   a189    |  7     15689  d1589   |  |Zz157     8    A19*    |  3    g167    4      | A169*  2     Yy159    |  |Zz127  Zzi27-9  6      |  17    5    hb1789   |  4   hc189     3      |  +-----------------------+----------------------+-----------------------+`

3. (9)r7c6 = (9-8)r9c6 = r9c8 - r7c9 = r6c9 - (8=147)r346c5 - r8c5 = (78-9)r9c68 = (9)r9c2 => -9 r7c23
4. Almost-almost skyscraper
[(9)r1c2 = r1c7 - r8c7 = r8c2]
(9-5)r1c8 = r3c9 - r8c9 = (527)b7p478
(9-5)r8c9 = (527)b7p478
=> -9 r9c2; lclste
Cenoman
Cenoman

Posts: 1483
Joined: 21 November 2016
Location: Paris, France