Editing Sudoku/Thorkil Naur (section)

== Command line interface to sdkSolve ==

The Main module contained in SdkMSol2.hs provides a command line
interface to the SuDoku solver. Here is an example of a call of
the solver that uses runhugs:
<pre>
runhugs SdkMSol2 \
  tn1 \
  Traditional 3 \
  -#123456789 \
  1-53---9- \
  ---6----- \
  ------271 \
  82------- \
  ---487--- \
  ------53- \
  23------- \
  --7-59--- \
  --6---8-4
</pre>
This is a command for a Linux system. A similar command can be used
under Windows. (I usually keep these long commmands in individual
command files, i.e. Shell scripts or BAT files.) And, of course,
SdkMSol2 can be compiled by GHC and run in a similar manner.

The first parameter "tn1" is simply a name for the puzzle used in the
output. In this case, the first (and so far only) SuDoku puzzle
invented by Yours Truly. The next parameter "Traditional" selects
the class of puzzle desired. Following parameters may be used to
qualify specific puzzles within the class, in this case the "3" which
selects the ordinary 9*9 SuDoku puzzle.

The remaining parameters lay out the initial contents of the
rectangular board. Parameters of the form
<pre>
  <character>#<list of characters>
</pre>
("#" is used rather than "=" which gives problems in BAT files) are
definitions where the first character is defined to represent the set
of characters listed. Thus, the parameter "-#123456789" defines "-"
to represent the set "123456789". Parameters not of this form
represent rows of the, generally rectangular, board: In such a row,
characters that have been "defined" represent their set, other
characters represent the set containing that single character.

(The command line interface thus restricts the elements used by the
solver to be individual characters. However, the solver itself is not
restricted to handle single-character elements.)

Notice that the puzzle class with parameters represents the
constraint sets used independently of the board, whose shape is
basically defined by the number of rows specified and their maximum
length. Conflicts are not verified explicitly, but generally result
in (sometimes obscure) runtime errors.

Selected lines from the output of running the above command:
<pre>
SdkMSol2: 2006-Jun-04 13.37
SdkMSol2(tn1)
  Height 9 Width 9
  1-53---9-
  ---6-----
  ------271
  82-------
  ---487---
  ------53-
  23-------
  --7-59---
  --6---8-4

tn1: Problem:
          1 123456789         5         3 123456789 123456789 123456789         9 123456789
  123456789 123456789 123456789         6 123456789 123456789 123456789 123456789 123456789
  123456789 123456789 123456789 123456789 123456789 123456789         2         7         1
          8         2 123456789 123456789 123456789 123456789 123456789 123456789 123456789
  123456789 123456789 123456789         4         8         7 123456789 123456789 123456789
  123456789 123456789 123456789 123456789 123456789 123456789         5         3 123456789
          2         3 123456789 123456789 123456789 123456789 123456789 123456789 123456789
  123456789 123456789         7 123456789         5         9 123456789 123456789 123456789
  123456789 123456789         6 123456789 123456789 123456789         8 123456789         4

tn1: Closure by field:
...
      1    78     5     3    27    28     4     9     6
     79   479     2     6  1479    14     3     8     5
    369  4689  3489   589    49   458     2     7     1
      8     2   139   159  1369  1356  1679     4    79
   3569  1569   139     4     8     7   169    16     2
    679 14679   149   129  1269   126     5     3     8
      2     3    18    18    46    46    79     5    79
      4    18     7   128     5     9    16   126     3
     59    59     6     7   123   123     8    12     4


tn1: Solutions:
  1 7 5 3 2 8 4 9 6
  9 4 2 6 7 1 3 8 5
  3 6 8 5 9 4 2 7 1
  8 2 9 1 3 5 6 4 7
  6 5 3 4 8 7 9 1 2
  7 1 4 9 6 2 5 3 8
  2 3 1 8 4 6 7 5 9
  4 8 7 2 5 9 1 6 3
  5 9 6 7 1 3 8 2 4


tn1: Total of 1 solutions
tn1: CPU Used: 53.4
</pre>
Thus, the problem is stated (in two different ways), the sequence of
intermediate boards resulting from performing field reduction on the
initial board is printed and, finally, all the solutions are printed.

(And since field reduction is also carried out, starting from the
initial board, as part of finding the solution, field reduction of
the initial board is actually carred out twice. Something that may be
changed by editing the sdkProcessSuDoku function.)

Here is an example of a command for solving a 16*16 SuDoku puzzle:
<pre>
runhugs SdkMSol2 \
  MasterSUDOKU_106_20051208 \
  Traditional 4 \
  -#0123456789ABCDEF \
  --6--37--B-C--E- \
  -C4A08D-5-7-2--- \
  -9--F----0--C1-- \
  -1E8--6-2D-4--5- \
  F-CBE---12-39-7- \
  -A8-B-----F7---1 \
  7-D4-9---C-0---8 \
  --------D-9--B-- \
  --2--0-9-------- \
  E---8-A---4-12-B \
  4---67-----F-90- \
  -0-FD-C1---E38-5 \
  -B--4-97-E--80A- \
  --F0--2----9--3- \
  ---E-F-3-A0B6C1- \
  -4--C-0--81--F--
</pre>
The final example uses the clover class:
<pre>
runhugs SdkMSol2 \
  JuleSuDoku_Fem_I_En_20060102 \
  Clover 3 \
  -#123456789 \
  ---6327-1...--7---23- \
  --24--5-6...4--1----- \
  --85---9-...1-5-8--7- \
  94----127...-6----8-5 \
  1-5------...-3---714- \
  87--9----...-41-62-97 \
  5873-------3----3--19 \
  --4--8----4----52--6- \
  2---65-----9---7--58- \
  ......5-----12-...... \
  ......-8---67-9...... \
  ......--1372---...... \
  64---9----14----4---- \
  --263-------------74- \
  -93-4----93----5-3--2 \
  ----68-7-...2-5--8-9- \
  ---------...84--9-57- \
  5--3--84-...-----5-26 \
  --54-36--...7-------- \
  2--9-5--7...-5438-61- \
  -3782----...--37694--
</pre>
Notice the dots (".") used. They do not enter any constraint sets,
but are needed to fill out the board.