## Hitori

For fans of all other kinds of logic puzzles
Here a walkthrough for the first Hitori. It will invent you in possible techniques to find the right steps. I guess you not need for the second puzzle so much time, if go this walkthrough. I use is most cases the names of a special techniques which are used by Spiral Mile. Some techniques are unknown there, some names to vague or not the same as used in the sudoku community:

Pyrrhon

Naked Singles (=circle sets) and Forbidden adjazents (= set circle) are skipped.
Weak black link = maximal one cell can be black
Weak white link = maximal one cell can be white
Strong link = one cell must be black, the other one must be white

Static:

Edge Triple R1C67, R2C6 => R1C5 white
Sandwich Triples: R1C678 => R1C7 = 7, R1C68 black
Sandwich Pairs: R4C46 = 6 => R4C5 white, R46C8 = 1 => R5C8 white
Pair Isolation R34C8 => R6C8 <> 1, R1C67 => R1C3 <> 7
Interacting Pair of Adjazent Pairs (generalization of Pair Isolation): R1C1, R2C1, R4C1, R5C1 => R8C1 <> 1

Dynamic:

Triple Split of R3C2 and weak black link R2C2 R3C1 => R3C2 black, R2C2, R3C1 = 4
Edge Closure: R2C7 black would split the grid = R2C7 white
different naked singles (=circle sets) and forbidden adjazents (=set circle)
Skyscraper with black cells, strong links in R67C2 and R67C3
and weak black cell links in R6C23, R78C3 and between R7C2 R8C3 (forbidden split) => R8C3 <> black
Skyscraper with black cells, strong links R34C7 and R34C8, and weak black links in R3C78, T45C7 and between R4C8 R5C7 (forbidden split) => R5C7 <> black
Mid Closure: R6C4 black would split the grid = R6C4 white
Corner Closure: R8C4 black would split the grid = R8C4 white

12x84x7x
x415x763
4x2x75x1
87362x5x
x5x28316
7x81x24x
26x75x34
x173x82x
Pyrrhon

Posts: 240
Joined: 26 April 2006

Anyone who likes hitori should perhaps try heyawake. It uses two of hitori's rules: black cells can only touch diagonally, and all white cells must be connected.
Sabreman64

Posts: 28
Joined: 22 July 2005

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