## All Chains are not Equal

Post puzzles for others to solve here.

### All Chains are not Equal

I have been adding a new (to me) type of chain to my generator which doesn't seem to be recognised by Sudoku Explainer.

Anyway, SE uses a total of four chains to solve the following puzzle, but it was generated with a single chain:

Code: Select all
`010002000067000080009603005900080500000100070002004060004009000700050930000000020`

What is this mystery chain?
civiliza

Posts: 64
Joined: 25 October 2010

### Re: All Chains are not Equal

There are many chains but two ur's and a bug will solve it.
dan

ArkieTech

Posts: 3355
Joined: 29 May 2006
Location: NW Arkansas USA

### Re: All Chains are not Equal

Your post lacks much. Still, let's see where it goes.

Code: Select all
` +-----------------------+ | . 1 . | . . 2 | . . . | | . 6 7 | . . . | . 8 . | | . . 9 | 6 . 3 | . . 5 | |-------+-------+-------| | 9 . . | . 8 . | 5 . . | | . . . | 1 . . | . 7 . | | . . 2 | . . 4 | . 6 . | |-------+-------+-------| | . . 4 | . . 9 | . . . | | 7 . . | . 5 . | 9 3 . | | . . . | . . . | . 2 . | +-----------------------+   c4    Hidden Pair                     =  59   r26c4   c5b2  Locked Candidate 1              <> 4    r9c5 r2  b2  Locked Candidate 1              <> 5    r2c1   c5b2  Locked Candidate 1              <> 7    r679c5   c6b8  Naked  Pair                     <> 18   r79c5 r5  b4  Locked Candidate 1              <> 8    r5c79 r7  b9  Locked Candidate 2              <> 1    r9c79   c28   X-Wing                          <> 4    r3c157,r4c9 <17+4>  XY-Wing  r3c5/r1c5+r3c8         <> 4    r1c9 r89c36  <18> UR Type 1.2224             <> 18   r9c3 <45+3>  XYZ-Wing r1c1/r1c3+r5c1         <> 3    r2c1 r1  b1  Hidden Pair                     =  35   r1c13 r19c13  <35> UR Type 1.2224             <> 35   r9c1 r7  b7  Locked Candidate 1              <> 3    r7c45 +--------------------------------------------------------------+ |  5     1     3     |  8     4     2     |  6     9     7     | |  24    6     7     |  9     1     5     |  234   8     234   | |  28    48    9     |  6     7     3     |  12    14    5     | |--------------------+--------------------+--------------------| |  9     34    6     |  23    8     7     |  5     14    123   | |  34    5     8     |  1     239   6     |  234   7     2349  | |  1     7     2     |  5     39    4     |  38    6     389   | |--------------------+--------------------+--------------------| |  368   38    4     |  27    26    9     |  178   5     18    | |  7     2     1     |  4     5     8     |  9     3     6     | |  68    9     5     |  37    36    1     |  478   2     48    | +--------------------------------------------------------------+ # 40 eliminations remain 4-SI S-Wing: (3)r5c1 = r4c2 - r4c4 = r9c4 - (3=6)r9c5 - r7c5 = (6)r7c1  =>  r7c1<>3   c9    Naked  Pair                     <> 23   r56c9         BUG+1                           =  8    r9c7`

So, a simple chain is all that's needed besided non-chain solving techniques.
daj95376
2014 Supporter

Posts: 2624
Joined: 15 May 2006