Merge pull request #2136 from fluca1978/pwc75

Pwc75

4 files changed, 141 insertions, 0 deletions

diff --git a/challenge-075/luca-ferrari/blog-1.txt b/challenge-075/luca-ferrari/blog-1.txt
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--- /dev/null
+++ b/challenge-075/luca-ferrari/blog-1.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2020/08/24/PerlWeeklyChallenge75.html#task1
diff --git a/challenge-075/luca-ferrari/blog-2.txt b/challenge-075/luca-ferrari/blog-2.txt
new file mode 100644
index 0000000000..d96d2273a8
--- /dev/null
+++ b/challenge-075/luca-ferrari/blog-2.txt
@@ -0,0 +1 @@
+https://fluca1978.github.io/2020/08/24/PerlWeeklyChallenge75.html#task2
diff --git a/challenge-075/luca-ferrari/raku/ch-1.p6 b/challenge-075/luca-ferrari/raku/ch-1.p6
new file mode 100644
index 0000000000..b52a91d40c
--- /dev/null
+++ b/challenge-075/luca-ferrari/raku/ch-1.p6
@@ -0,0 +1,81 @@
+#!raku
+
+sub find-solutions( Int :$sum, :@coins ) {
+    my @solutions;
+
+    # add all the 'one coin' solutions
+    @solutions.push: [ $_ xx ( $sum / $_ ) ] for @coins.grep( $sum %% * );
+
+
+    # now inspect all the other cases
+    for @coins.grep(  $sum !%% * ).sort( { $^b <=> $^a } ) -> $current-coin {
+        next if $current-coin > $sum;
+        my @current-solution;
+        @current-solution.push: $current-coin;
+
+        for @coins.grep( * !~~ $current-coin ).sort( { $^b <=> $^a } ) {
+            my $current-sum = [+] @current-solution;
+            # try to add the same number over and over again
+            while ( ( $current-sum + $_ ) <= $sum ) {
+                @current-solution.push: $_ ;
+                $current-sum = [+] @current-solution;
+            }
+
+            if ( $current-sum == $sum  ) {
+                # use a new array to clone it, so I can delete the last value and continue over
+                @solutions.push: Array.new: @current-solution.sort;
+                @current-solution[ *-1 ]:delete;
+                next;
+            }
+        }
+
+    }
+
+
+    # last step: decompose every number in a solution into other numbers
+    my @decomposed-solutions;
+    for @solutions -> @current-solution {
+        for 0 ..^ @current-solution.elems -> $switching-index {
+
+            my $current-coin = @current-solution[ $switching-index ];
+            next if $current-coin ~~ 1;
+
+            for @coins.grep( $current-coin %% * ) {
+                next if $_ ~~ $current-coin;
+                my @new-solution = Array.new: @current-solution;
+                @new-solution[ $switching-index ]:delete;
+                @new-solution[ $switching-index ] = | ( $_ xx ( $current-coin / $_ ) );
+                @decomposed-solutions.push: [ @new-solution.sort ];
+            }
+        }
+    }
+
+
+    # now build something unique
+    my %unique-solutions;
+    for @decomposed-solutions {
+        %unique-solutions{ "{ $_ }" } = $_;
+    }
+
+    for @solutions {
+        %unique-solutions{ "{ $_ }" } = $_;
+    }
+
+
+    %unique-solutions.values;
+}
+
+
+
+
+sub MAIN( Int $S where { $S > 0 },
+          *@C where { @C.grep( * ~~ Int ).elems == @C.elems } ) {
+    say "Coins are { @C } that must give sum $S";
+
+    my @solutions;
+
+    @solutions = find-solutions( coins => @C, sum => $S );
+
+    @solutions.join( "\n" ).say;
+
+}
diff --git a/challenge-075/luca-ferrari/raku/ch-2.p6 b/challenge-075/luca-ferrari/raku/ch-2.p6
new file mode 100644
index 0000000000..14cf0bef95
--- /dev/null
+++ b/challenge-075/luca-ferrari/raku/ch-2.p6
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+#!raku
+
+class Histogram {
+    has Int $.column;
+    has Int $.height;
+
+    method Str() { "Histogram $!height Column $!column"; }
+}
+
+
+class Rectangle {
+    has Int $.height;
+    has Int $.base;
+
+    method area() { $!height * $!base }
+    method Str()  { "Rectangle with base $!base and height $!height ($!base x $!height)" }
+}
+
+
+sub MAIN( *@A
+          where { @A.grep( * ~~ Int ).elems == @A.elems  && @A.grep( *.Int >= 1 ) } ) {
+    say "Numbers are { @A }";
+
+    my Histogram @histograms;
+    my $column = 1;
+    for @A {
+        @histograms.push: Histogram.new: column => $column, height => $_.Int;
+    }
+
+
+    my Rectangle @rectangles;
+    my ( $current-height, $current-width ) = Nil, Nil;
+
+    for 0 ..^ @histograms.elems -> $current-index {
+        ( $current-height, $current-width ) = @histograms[ $current-index ].height, 0;
+
+
+        for 0 ..^ @histograms.elems {
+            next if $_ < $current-index && @histograms[ $_ ].height < $current-height;
+            if @histograms[ $_ ].height < $current-height {
+                last;
+            }
+            else {
+                $current-width++;
+            }
+        }
+
+        @rectangles.push: Rectangle.new( height => $current-height,
+                                         base => $current-width );
+    }
+
+
+
+    # get the first one with the biggest area
+    @rectangles.sort( { $^b.area <=> $^a.area } ).first.put;
+
+
+}