From 7ebfde42fe733e489a38644eaa666c1bc1e2816b Mon Sep 17 00:00:00 2001
From: Jeremy Rand <jeremy@rand-family.com>
Date: Thu, 16 Jul 2015 13:17:31 -0500
Subject: [PATCH] Add a perl script to generate puzzles.

---
 a2sudoku/generateSudoku.pl | 141 +++++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100755 a2sudoku/generateSudoku.pl

diff --git a/a2sudoku/generateSudoku.pl b/a2sudoku/generateSudoku.pl
new file mode 100755
index 0000000..aa8e187
--- /dev/null
+++ b/a2sudoku/generateSudoku.pl
@@ -0,0 +1,141 @@
+#!/usr/bin/perl -w
+#
+# To use this generator, first you need node.js and this
+# sudoku generator:
+#
+#    https://github.com/dachev/sudoku
+#
+# You should be able to get it with:
+#
+#     sudo npm install sudoku
+#
+# Once you have that, you can generate 300 puzzles fairly
+# quickly with the following from the shell:
+#
+#     i=1 
+#     while [ $i -lt 300 ]
+#     do
+#         node lib/node_modules/sudoku/bin/sudoku.js
+#         i=`expr $i + 1`
+#     done > /tmp/puzzles.txt
+#
+# But the output of this isn't ready for a2sudoku.  To
+# turn it into the right definitions for a2sudoku, you
+# need to pass it through this script:
+#
+#     generateSudoku.pl /tmp/puzzles.txt > /tmp/newpuzzles.c
+#
+# Then, you just need to copy those puzzles into puzzles.c
+# in the source-code and you have refreshed the puzzles.
+#
+
+
+use strict;
+
+
+my @known;
+my @solution;
+my @easy;
+my @medium;
+my @hard;
+
+
+sub getKnown
+{
+    my @result;
+    my $i;
+    my $j;
+    my $line;
+
+    for ($i = 0; $i < 3; $i++) {
+        for ($j = 0; $j < 3; $j++) {
+            $line = <>;
+            chomp $line;
+            $line =~ s/_/P/g;
+            $line =~ s/[1-9]/S/g;
+            push(@result, split(/ +/, $line));
+        }
+        $line = <>;
+    }
+
+    return @result;
+}
+
+
+sub getSolution
+{
+    my @result;
+    my $i;
+    my $j;
+    my $line;
+
+    for ($i = 0; $i < 3; $i++) {
+        for ($j = 0; $j < 3; $j++) {
+            $line = <>;
+            chomp $line;
+            push(@result, split(/ +/, $line));
+        }
+        $line = <>;
+    }
+
+    return @result;
+}
+
+
+sub generatePuzzle
+{
+    my $i;
+    my $result = 
+"    {\n" .
+"        {\n" .
+"            ";
+
+    for ($i = 0; $i <= $#known; $i++) {
+        $result .= $known[$i] . "VAL(" . $solution[$i] . "),";
+
+        if ($i == $#known) {
+            $result .= "\n        }\n    },\n";
+        } elsif (($i % 27) == 26) {
+            $result .= "\n\n            ";
+        } elsif (($i % 9) == 8) {
+            $result .= "\n            ";
+        } elsif (($i % 3) == 2) {
+            $result .= " ";
+        }
+    }
+
+    return $result;
+}
+
+
+# Turns out I run out of memory pretty quickly.  I should look at
+# putting the puzzles on disk and loading them rather than building
+# them in.  For now, enforce a limit to make sure we don't exceed
+# limits.
+my $limit = 50;
+while (<>) {
+    chomp;
+    if (/^PUZZLE:/) {
+        @known = &getKnown;
+    }
+
+    if (/^SOLUTION:/) {
+        @solution = &getSolution;
+    }
+
+    if ((/^RATING: 0/) &&
+        ($#easy < $limit)) {
+        push(@easy, &generatePuzzle);
+    } elsif ((/^RATING: 1/) &&
+             ($#medium < $limit)) {
+        push(@medium, &generatePuzzle);
+    } elsif ((/^RATING: /) && 
+             ($#hard < $limit)) {
+        push(@hard, &generatePuzzle);
+    }
+}
+
+
+print "tPuzzle easyPuzzles[] = {\n" . join("", @easy) . "};\n\n\n";
+print "tPuzzle mediumPuzzles[] = {\n" . join("", @medium) . "};\n\n\n";
+print "tPuzzle hardPuzzles[] = {\n" . join("", @hard) . "};\n\n\n";