- Added solution by Ulrich Rieke.

1 files changed, 87 insertions, 0 deletions

diff --git a/challenge-092/ulrich-rieke/raku/ch-2.raku b/challenge-092/ulrich-rieke/raku/ch-2.raku
new file mode 100644
index 0000000000..f7ff12cc41
--- /dev/null
+++ b/challenge-092/ulrich-rieke/raku/ch-2.raku
@@ -0,0 +1,87 @@
+use v6 ;
+
+sub enterData( ) {
+  say "Enter intervals!" ;
+  my $S = $*IN.get ;
+  while ( $S !~~ /('(' (\d+) ',' (\d+) ')' ',' \s*)+/ ) {
+      say "Wrong entry! Enter non overlapping intervals!" ;
+      $S = $*IN.get ;
+  }
+  say 'Enter $N! ' ;
+  my $N = $*IN.get ;
+  while ( $N !~~ /'(' (\d+) ',' (\d+) ')'/ ) {
+      say "Enter one pair, enclosed in brackets!" ;
+      $N = $*IN.get ;
+  }
+  return ( $S , $N ) ;
+}
+
+sub createSet( Str $pair ) {
+  $pair ~~ /'(' (\d+) ',' (\d+) ')'/  ;
+  return ($0.Int .. $1.Int).Set ;
+}
+
+sub stringFromSet( Set $theSet --> Str ) {
+  return ('(' ~ ~$theSet.min.key ~ ',' ~$theSet.max.key ~ ')' );
+}
+
+my ($S , $N) = enterData( ) ;
+my @allSets = $S.split( /',' \s+/).map( { createSet( $_ ) } ) ;
+my Set $nset = createSet( $N ) ;
+my Bool $unionFormed = False ;
+my @allUnions ;
+for @allSets -> $elem {
+  if ( my $inters = $elem (&) $nset ) {
+      my $union = $elem (|) $nset ;
+      $unionFormed = True ;
+      @allUnions.push( $union ) ;
+  }
+  else {
+      @allUnions.push( $elem ) ;
+  }
+}
+my $output ; #that's the string for the final output
+if ( $unionFormed == False ) { #not a single union with $N
+  @allUnions.push( $nset ) ;
+  @allUnions .= sort( {$^a.min.key <=> $^b.min.key} ) ;
+#we can output the final result, no intersections and therefore no unions
+  for @allUnions -> $elem {
+      $output ~= (stringFromSet( $elem ) ~ " ") ;
+  }
+}
+else {
+  if ( @allUnions.elems == 1 ) {
+      $output = stringFromSet( @allUnions[0] ) ;
+  }
+  if ( @allUnions.elems == 2 ) {
+      if ( my $inters = @allUnions[ 0 ] (&) @allUnions[ 1 ] ) {
+    my $union = @allUnions[ 0 ] (|) @allUnions[ 1 ] ;
+    $output = stringFromSet( $union ) ;
+      }
+      else {
+    @allUnions.map( { $output ~= (stringFromSet( $_ ) ~ " ") } ) ;
+      }
+  }
+  if ( @allUnions.elems > 2 ) {
+      my @finalElements ; #takes the results of pairwise union forming
+      my $lastelem = @allUnions.shift( ) ;
+      while ( @allUnions ) {
+    my $nextelem = @allUnions.shift ;
+    if ( my $inters = $lastelem (&) $nextelem ) {
+        my $union = $lastelem (|) $nextelem ;
+        $lastelem = $union ;
+    }
+    else {
+        @finalElements.push( $lastelem ) ;
+        $lastelem = $nextelem ;
+    }
+      }
+      @finalElements.push( $lastelem ) ;
+      for @finalElements -> $elem {
+    $output ~= stringFromSet( $elem ) ~ " " ;
+      }
+  }
+}
+$output .= trim ;
+$output ~~ s:g/\s/\, / ;
+say $output ;