PWC 281

Task 1 Raku done
Task 2 Raku done

5 files changed, 106 insertions, 72 deletions

diff --git a/challenge-281/luca-ferrari/blog-1.txt b/challenge-281/luca-ferrari/blog-1.txt
new file mode 100644
index 0000000000..94e5e0284e
--- /dev/null
+++ b/challenge-281/luca-ferrari/blog-1.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/08/08/PerlWeeklyChallenge281.html#task1
diff --git a/challenge-281/luca-ferrari/blog-2.txt b/challenge-281/luca-ferrari/blog-2.txt
new file mode 100644
index 0000000000..ed57216f56
--- /dev/null
+++ b/challenge-281/luca-ferrari/blog-2.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2024/08/08/PerlWeeklyChallenge281.html#task2
diff --git a/challenge-281/luca-ferrari/pljava/pom.xml b/challenge-281/luca-ferrari/pljava/pom.xml
deleted file mode 100644
index 96ca25649f..0000000000
--- a/challenge-281/luca-ferrari/pljava/pom.xml
+++ /dev/null
@@ -1,72 +0,0 @@
-
-<project
- xmlns="http://maven.apache.org/POM/4.0.0"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation= "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" >
-  <modelVersion>4.0.0</modelVersion>
-
-  <groupId>PWC</groupId>
-  <artifactId>
-    PWC280
-  </artifactId>
-  <version>
-    1
-  </version>
-
-  <name>Perl Weekly Challenge 280 with package PWC280</name>
-  <description>Implementation of the tasks in PL/Java for PWC 280</description>
-
-  <properties>
-    <project.build.sourceEncoding>US-ASCII</project.build.sourceEncoding>
-  </properties>
-
-  <dependencies>
-    <dependency>
-      <groupId>org.postgresql</groupId>
-      <artifactId>pljava-api</artifactId>
-      <version>1.6.6</version>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <version>3.8.1</version>
-        <configuration>
-          <release>9</release>
-        </configuration>
-      </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <version>2.6</version>
-        <configuration>
-          <archive>
-            <manifest>
-              <!-- This identifies and version-stamps the jar.
-                 Not essential, but easy and useful. -->
-              <addDefaultImplementationEntries>
-                true
-              </addDefaultImplementationEntries>
-            </manifest>
-
-            <manifestSections>
-              <!-- This identifies a file in the jar named
-                 pljava.ddr as an SQLJDeploymentDescriptor. -->
-              <manifestSection>
-                <name>pljava.ddr</name>
-                <manifestEntries>
-                  <SQLJDeploymentDescriptor>
-                    true
-                  </SQLJDeploymentDescriptor>
-                </manifestEntries>
-              </manifestSection>
-            </manifestSections>
-          </archive>
-        </configuration>
-      </plugin>
-    </plugins>
-  </build>
-</project>
diff --git a/challenge-281/luca-ferrari/raku/ch-1.raku b/challenge-281/luca-ferrari/raku/ch-1.raku
new file mode 100644
index 0000000000..7da9df1ce9
--- /dev/null
+++ b/challenge-281/luca-ferrari/raku/ch-1.raku
@@ -0,0 +1,23 @@
+#!raku
+
+#
+# Perl Weekly Challenge 281
+# Task 1
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-281>
+#
+
+sub MAIN( Str $coordinates where { $coordinates ~~ / ^ <[a .. h]> <[ 1 .. 8 ]> $/ } ) {
+    my %chessboard;
+    my $value = False;
+    for 1 .. 8 -> $row {
+	$value = $row %% 2 ?? True !! False;
+	for 'a' .. 'h' -> $column {
+	    %chessboard{ $column ~ $row } = $value;
+	    $value = ! $value;
+	}
+    }
+
+    %chessboard{ $coordinates }.say;
+
+}
diff --git a/challenge-281/luca-ferrari/raku/ch-2.raku b/challenge-281/luca-ferrari/raku/ch-2.raku
new file mode 100644
index 0000000000..6f1136fcda
--- /dev/null
+++ b/challenge-281/luca-ferrari/raku/ch-2.raku
@@ -0,0 +1,81 @@
+#!raku
+
+#
+# Perl Weekly Challenge 281
+# Task 2
+#
+# See <https://perlweeklychallenge.org/blog/perl-weekly-challenge-281>
+#
+
+
+sub compute-end-points( $start ) {
+    my @end-points;
+    my @valid-columns = 'a' .. 'h';
+
+    $start ~~ / ^ $<column>=( <[a..h]> ) $<row>=( <[1..8]> ) $ /;
+    my $row = $<row>.Int;
+    my $column = $<column>.Str;
+
+    return Nil if ( $row > 8 || $row < 1 || ! @valid-columns.grep( { $_ ~~ $column } ) );
+
+    # at which index is the current column labeled with a letter?
+    $column    = @valid-columns.grep( { $_ ~~ $column }, :k )[ 0 ];
+
+    my @moves = [ +1, -2 ], [ +1, +2 ],
+		[ +2, -1 ], [ +2, +1 ],
+		[ -1, -2 ], [ -1, +2 ],
+		[ -2, -1 ], [ -2, +1 ];
+
+    @end-points = @moves.map(
+	{  [ @valid-columns[ $_[ 0 ] + $column ], $_[ 1 ] + $row ] } )
+		   .grep( { $_[ 0 ] && @valid-columns.grep( * ~~ $_[ 0 ] ) && 1 <= $_[ 1 ] <= 8 } )
+		   .map( { $_[ 0 ] ~ $_[ 1 ] } );
+		   ;
+    return @end-points;
+}
+
+
+sub MAIN( Str $start,
+	  Str $end,
+	  :$verbose
+			  where { $start !~~ $end
+				  and $start ~~ / ^ <[a..h]> <[1..8]> $ /
+				  and $end ~~ / ^ <[a..h]> <[1..8]> $ / }
+			   ) {
+
+
+    my @end-points = compute-end-points( $start );
+
+    my @paths;
+    @paths = @end-points.map( $start ~ '-' ~ * );
+
+    my @new-paths;
+    my $found = False;
+    my $debug = 0;
+    while ( ! $found ) {
+	for @paths.sort -> $current-path  {
+	    my $next = $current-path.split( '-' )[ * - 1 ];
+	    my @ends = compute-end-points( $next ).grep( { $_ ne $start && $_ ne $next } );
+	    @new-paths.push: $current-path ~ '-'  ~ $_ for @ends;
+	}
+
+	@paths = @new-paths;
+	@new-paths = ();
+	$found = @paths.grep( * ~~ / $end $ / );
+
+    }
+
+
+
+    my %possible-moves;
+    for @paths.grep( * ~~ / $end $ / ) {
+	%possible-moves{ $_.split( '-' ).elems }.push: $_;
+    }
+
+    my $min-moves = %possible-moves.keys.min;
+    $min-moves.say;
+    if ( $verbose ) {
+	"possible moves:".say;
+	%possible-moves{ $min-moves  }.sort.join( "\n" ).say;
+    }
+}