- Added solutions by Ulrich Rieke.

2 files changed, 224 insertions, 0 deletions

diff --git a/challenge-044/ulrich-rieke/raku/ch-1.p6 b/challenge-044/ulrich-rieke/raku/ch-1.p6
new file mode 100644
index 0000000000..e80d16b88b
--- /dev/null
+++ b/challenge-044/ulrich-rieke/raku/ch-1.p6
@@ -0,0 +1,204 @@
+use v6 ;
+
+#in order to create the analogon of list comprehensions, I had to create
+#various functions to take account of differing numbers of digit
+#combinations. Unfortunately, this led to code repetition.
+#to print out the results of the gather-take loops turned out to be more
+#difficult than originally envisaged
+#somehow you have to circumvent the fact the immutability of resulting
+#strings
+
+sub testSubSequences_8( @numbers ) {
+  my @sources ;
+  for (0..7 ) -> $i {
+      @sources.push( @numbers[ $i ] , -@numbers[ $i ] ) ;
+  }
+  my  @fittingnumbers = gather {
+    for @sources[0,1] -> $n0 {
+        for @sources[2,3] -> $n1 {
+            for @sources[4,5] -> $n2 {
+                for @sources[6,7] -> $n3 {
+                    for @sources[8,9] -> $n4 {
+                        for @sources[10,11] -> $n5 {
+                            for @sources[12,13] -> $n6 {
+                                for @sources[14,15] -> $n7 {
+                                    if ( $n0 + $n1 + $n2 + $n3 + $n4 + $n5 + $n6 + $n7 ) == 100 {
+                                        take $n0 , $n1 , $n2 , $n3 , $n4 , $n5 , $n6 , $n7 ;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+  }
+  if @fittingnumbers {
+      for @fittingnumbers -> @array {
+        my $str = join '+' , @array ;
+        $str ~~ s:g/\+\-/\-/ ;
+        say $str ;
+      }
+  }
+}
+
+sub testSubSequences_7( @numbers ) {
+  my @sources ;
+  for (0..6 ) -> $i {
+      @sources.push( @numbers[ $i ] , -@numbers[ $i ] ) ;
+  }
+  my @fittingnumbers = gather {
+    for @sources[0, 1] -> $n0 {
+        for @sources[2 , 3] -> $n1 {
+            for @sources[4 , 5] -> $n2 {
+                for @sources[6 , 7] -> $n3 {
+                    for @sources[8 , 9] -> $n4 {
+                        for @sources[10 , 11 ] -> $n5 {
+                            for @sources[12 , 13] -> $n6 {
+                                if ( $n0 + $n1 + $n2 + $n3 + $n4 + $n5 + $n6 ) == 100 {
+                                    take $n0 , $n1 , $n2 , $n3 , $n4 , $n5 , $n6 ;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+  }
+  if @fittingnumbers {
+      for @fittingnumbers -> @array {
+        my $str = join '+', @array ;
+        $str ~~ s:g/\+\-/\-/ ;
+        say $str ;
+      }
+  }
+}
+
+sub testSubSequences_6( @numbers ) {
+  my @sources ;
+  for (0..5 ) -> $i {
+      @sources.push( @numbers[ $i ] , -@numbers[ $i ] ) ;
+  }
+  my @fittingnumbers = gather {
+    for @sources[0,1] -> $n0 {
+        for @sources[2 , 3] -> $n1 {
+            for @sources[4 , 5] -> $n2 {
+                for @sources[6 , 7] -> $n3 {
+                    for @sources[8 , 9] -> $n4 {
+                        for @sources[10, 11] -> $n5 {
+                            if ( $n0 + $n1 + $n2 + $n3 + $n4 + $n5 ) == 100 {
+                                take $n0 , $n1 , $n2 , $n3 , $n4 , $n5 ;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+  }
+  if @fittingnumbers {
+      for @fittingnumbers -> @array {
+        my $str = join '+' , @array ;
+        $str ~~ s:g/\+\-/\-/ ;
+        say $str ;
+      }
+  }
+}
+
+sub testSubSequences_5( @numbers ) {
+  my @sources ;
+  for (0..4 ) -> $i {
+      @sources.push( @numbers[ $i ] , -@numbers[ $i ] ) ;
+  }
+  my @fittingnumbers = gather {
+    for @sources[0, 1] -> $n0 {
+        for @sources[2 , 3] -> $n1 {
+            for @sources[4 , 5] -> $n2 {
+                for @sources[6 , 7] -> $n3 {
+                    for @sources[8 , 9] -> $n4 {
+                        if ( $n0 + $n1 + $n2 + $n3 + $n4 ) == 100 {
+                            take $n0 , $n1 , $n2 , $n3 , $n4 ;
+                        }
+                    }
+                }
+            }
+        }
+    }
+  }
+  if @fittingnumbers {
+      for @fittingnumbers -> @array {
+        my $str = join '+' , @array ;
+        $str ~~ s:g/\+\-/\-/ ;
+    s   ay $str ;
+      }
+  }
+}
+
+sub testSubSequences_4( @numbers ) {
+  my @sources ;
+  for (0..3 ) -> $i {
+      @sources.push( @numbers[ $i ] , -@numbers[ $i ] ) ;
+  }
+  my @fittingnumbers = gather {
+    for @sources[0, 1] -> $n0 {
+        for @sources[2 , 3] -> $n1 {
+            for @sources[4, 5] -> $n2 {
+                for @sources[6, 7] -> $n3 {
+                    if ( $n0 + $n1 + $n2 + $n3 ) == 100 {
+                        take $n0 , $n1 , $n2 , $n3 ;
+                    }
+                }
+            }
+        }
+    }
+  }
+  if @fittingnumbers {
+      for @fittingnumbers -> @array {
+        my $str = join '+' , @array ;
+        $str ~~ s:g/\+\-/\-/ ;
+        say $str ;
+      }
+  }
+}
+
+#function to find the substrings and numbers according to length sequences
+sub findNumbers( Str $digits , $seq ) {
+  my @numbers ;
+  my $current = 0 ;
+  for $seq.Array -> $i {
+      @numbers.push( $digits.substr( $current , $i ).Int) ;
+      $current += $i ;
+  }
+  return @numbers ;
+}
+
+
+my $digits = "123456789" ;
+#a combination of 3 three-digit-numbers will not result in 100 as a sum!
+#therefore, the likely combinations in length are : ( all summing up to 9)
+my @likelyCombos = ( (1 , 2 , 2 , 2 , 2 ) , (1 , 1 , 1 , 1 , 1 , 2 , 2 ),
+      (3 , 2 , 2 , 2 ) , ( 1 , 2 , 3 , 2 , 1 ) , ( 3 , 3 , 2 , 1 ) ,
+      ( 3 , 3 , 1 , 1 , 1 ) , (1 , 1 , 1 , 1 , 1 , 1, 1, 2) ) ;
+#we now permutate these combinations and form substrings , that is numbers
+#accordingly, preserving the order of digits
+
+#the dispatcher helps to select the right list comprehension depending on
+#length of the @numbers array!
+my %dispatcher =
+  4 => &testSubSequences_4 ,
+  5 => &testSubSequences_5 ,
+  6 => &testSubSequences_6 ,
+  7 => &testSubSequences_7 ,
+  8 => &testSubSequences_8 ;
+
+say "+ and - can be inserted in the following ways:" ;
+for @likelyCombos -> $combo {
+  my $selectedOp = %dispatcher{ $combo.elems } ;
+  my @permus = $combo.permutations.unique(:with(&[eqv])) ;
+  for @permus -> $permutation {
+      my @numbers = findNumbers( $digits , $permutation ) ;
+      $selectedOp( @numbers ) ;
+  }
+}
diff --git a/challenge-044/ulrich-rieke/raku/ch-2.p6 b/challenge-044/ulrich-rieke/raku/ch-2.p6
new file mode 100644
index 0000000000..86225bbbc1
--- /dev/null
+++ b/challenge-044/ulrich-rieke/raku/ch-2.p6
@@ -0,0 +1,20 @@
+use v6 ;
+
+sub doublingSteps( Int $n is copy ) {
+  my $count = 0 ;
+  while ( $n < 200 ) {
+      $count++ ;
+      $n *= 2 ;
+  }
+  return ( $n div= 2 , --$count ) ;
+}
+
+#we assume that we go to a starting point in steps of 1 , then
+#keep doubling and then move forward to 200 in steps of 1
+sub computeSteps( Int $n is copy --> Int ) {
+  my @result = doublingSteps( $n ) ;
+  return ( $n - 1 + @result[1] + 200 - @result[0] ) ;
+}
+
+my $moves = (1..100).map( { computeSteps( $_ ) } ).sort( {$^a <=> $^b})[0] ;
+say "The minimum number of moves is $moves!" ;