Bonus track graph.

Fixes also some problems.

1 files changed, 51 insertions, 5 deletions

diff --git a/challenge-075/luca-ferrari/raku/ch-2.p6 b/challenge-075/luca-ferrari/raku/ch-2.p6
index 14cf0bef95..072ab8378a 100644
--- a/challenge-075/luca-ferrari/raku/ch-2.p6
+++ b/challenge-075/luca-ferrari/raku/ch-2.p6
@@ -12,8 +12,39 @@ class Rectangle {
     has Int $.height;
     has Int $.base;
 
+    has Range $.columns;
+
     method area() { $!height * $!base }
-    method Str()  { "Rectangle with base $!base and height $!height ($!base x $!height)" }
+    method Str()  { "Rectangle with base $!base and height $!height ($!base x $!height) {$!columns}" }
+}
+
+
+sub graph( Histogram :@histograms, Rectangle :$rectangle? ) {
+    my @lines;
+    my $max-height = max @histograms.map( { .height } );
+
+
+    while ( $max-height > 0 ) {
+        my @line;
+        @line.push: $max-height ~ '| ';
+
+        for @histograms {
+            my $column = .column;
+            my $height = .height;
+            my $to-print = $rectangle
+            && $column ~~ $rectangle.columns
+            && $rectangle.height >= $max-height
+            ?? ' X' !! ' #';
+            @line.push: .height >= $max-height ?? $to-print !! '  ';
+        }
+
+        @lines.push: @line.join;
+        $max-height--;
+    }
+
+    @lines.push: '---' x @histograms.elems;
+    @lines.push: '    ' ~ @histograms.map( { .column } ).join( ' ' );
+    @lines;
 }
 
 
@@ -24,35 +55,50 @@ sub MAIN( *@A
     my Histogram @histograms;
     my $column = 1;
     for @A {
-        @histograms.push: Histogram.new: column => $column, height => $_.Int;
+        @histograms.push: Histogram.new: column => $column++, height => $_.Int;
     }
 
 
     my Rectangle @rectangles;
     my ( $current-height, $current-width ) = Nil, Nil;
+    my ( $start-column, $end-column )      = Nil, Nil;
 
     for 0 ..^ @histograms.elems -> $current-index {
         ( $current-height, $current-width ) = @histograms[ $current-index ].height, 0;
+        ( $start-column, $end-column ) = $current-index + 1 , $current-index + 1;
+
 
+        # go backwards to the first histogram that has a good height
+        my $starting-index = $current-index;
+        while ( $starting-index > 0 &&  @histograms[ $starting-index ].height >= $current-height ) {
+            $starting-index--;
+        }
 
-        for 0 ..^ @histograms.elems {
+        for $starting-index ..^ @histograms.elems {
             next if $_ < $current-index && @histograms[ $_ ].height < $current-height;
             if @histograms[ $_ ].height < $current-height {
                 last;
             }
             else {
                 $current-width++;
+                $start-column = min $_ + 1 , $start-column;
+                $end-column   = max $_ + 1, $end-column;
             }
         }
 
         @rectangles.push: Rectangle.new( height => $current-height,
-                                         base => $current-width );
+                                         base => $current-width,
+                                         columns => $start-column .. $end-column  );
     }
 
 
 
     # get the first one with the biggest area
-    @rectangles.sort( { $^b.area <=> $^a.area } ).first.put;
+    my Rectangle $biggest = @rectangles.sort( { $^b.area <=> $^a.area } ).first;
+    $biggest.put;
 
+    # try to print the histogram
+    "Following is the graph of the histogram".say;
+    graph( histograms => @histograms, rectangle => $biggest ).join( "\n" ).say;
 
 }