Merge pull request #7484 from polettix/polettix/pwc201

Add polettix's solution to challenge-201

6 files changed, 148 insertions, 0 deletions

diff --git a/challenge-201/polettix/blog.txt b/challenge-201/polettix/blog.txt
new file mode 100644
index 0000000000..f17a8636ab
--- /dev/null
+++ b/challenge-201/polettix/blog.txt
@@ -0,0 +1 @@
+https://etoobusy.polettix.it/2023/01/26/pwc201-missing-numbers/
diff --git a/challenge-201/polettix/blog1.txt b/challenge-201/polettix/blog1.txt
new file mode 100644
index 0000000000..6f5fc4ec28
--- /dev/null
+++ b/challenge-201/polettix/blog1.txt
@@ -0,0 +1 @@
+https://etoobusy.polettix.it/2023/01/27/pwc201-penny-piles/
diff --git a/challenge-201/polettix/perl/ch-1.pl b/challenge-201/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..703b29f83f
--- /dev/null
+++ b/challenge-201/polettix/perl/ch-1.pl
@@ -0,0 +1,12 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+say for missing_numbers(@ARGV);
+
+sub missing_numbers (@array) {
+   my %set = map { $_ => 1 } @array;
+   grep { ! exists($set{$_}) } 0 .. @array;
+}
diff --git a/challenge-201/polettix/perl/ch-2.pl b/challenge-201/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..c80ec50a9c
--- /dev/null
+++ b/challenge-201/polettix/perl/ch-2.pl
@@ -0,0 +1,83 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+my $n = shift // 5;
+say scalar penny_piles_recursive($n)->@*;
+say scalar penny_piles_iterative($n)->@*;
+
+my $count = 0;
+my $it = penny_piles_iterator($n);
+while (my $seq = $it->()) {
+   #say "$seq->@*";
+   ++$count;
+}
+say $count;
+
+sub penny_piles_iterator ($n) {
+   my @trail;
+   my @stack = ($n);
+   return sub {
+      my $retval = undef;
+      while (@stack && ! $retval) {
+         $retval = [@trail] if $stack[-1] == 0;
+         if (@trail < @stack) { # initialize
+            my $min = @trail ? $trail[-1] : 1;
+            push @trail, $min;
+         }
+         else { # continue this frame's iteration
+            $trail[-1]++;
+         }
+         if ($trail[-1] <= $stack[-1]) { # "recurse"
+            push @stack, $stack[-1] - $trail[-1];
+         }
+         else { # "return"
+            pop @trail;
+            pop @stack;
+         }
+      }
+      return $retval;
+   };
+}
+
+sub penny_piles_iterative ($n) {
+   my @valid;
+   my @trail;
+   my @stack = ($n);
+   while (@stack) {
+      push @valid, [@trail] if $stack[-1] == 0;
+      if (@trail < @stack) { # initialize
+         my $min = @trail ? $trail[-1] : 1;
+         push @trail, $min;
+      }
+      else { # continue this frame's iteration
+         $trail[-1]++;
+      }
+      if ($trail[-1] <= $stack[-1]) { # "recurse"
+         push @stack, $stack[-1] - $trail[-1];
+      }
+      else { # "return"
+         pop @trail;
+         pop @stack;
+      }
+   }
+   return \@valid;
+}
+
+sub penny_piles_recursive ($n) {
+   my @valid;
+   my @trail;
+   sub ($n) {
+      push @valid, [@trail] if $n == 0;
+      my $min = @trail ? $trail[-1] : 1;
+      push @trail, $min;
+      while ($trail[-1] <= $n) {
+         __SUB__->($n - $trail[-1]);
+         ++$trail[-1];
+      }
+      pop @trail;
+   }->($n);
+   return \@valid;
+}
diff --git a/challenge-201/polettix/raku/ch-1.raku b/challenge-201/polettix/raku/ch-1.raku
new file mode 100644
index 0000000000..c75f58d113
--- /dev/null
+++ b/challenge-201/polettix/raku/ch-1.raku
@@ -0,0 +1,8 @@
+#!/usr/bin/env raku
+use v6;
+sub MAIN (*@args) { .put for missing-numbers(@args) }
+
+sub missing-numbers (@array) {
+   my $present = @array».Str.Set;
+   return [(0 .. @array.elems).grep({ $_.Str ∉ $present })];
+}
diff --git a/challenge-201/polettix/raku/ch-2.raku b/challenge-201/polettix/raku/ch-2.raku
new file mode 100644
index 0000000000..377af83015
--- /dev/null
+++ b/challenge-201/polettix/raku/ch-2.raku
@@ -0,0 +1,43 @@
+#!/usr/bin/env raku
+use v6;
+sub MAIN (Int $n where * > 0 = 5) {
+   class PennyPilesIterator { ... }
+   my $it = PennyPilesIterator.new($n);
+   while defined(my $seq = $it.next) {
+      $seq.say
+   }
+   put $it.count;
+}
+
+class PennyPilesIterator {
+   has @!trail is built;
+   has @!stack is built;
+   has $.count = 0;
+
+   method new ($n) { self.bless(trail => [], stack => [$n]) }
+
+   method next () {
+      my $retval = Nil;
+      while (@!stack && ! $retval) {
+         if @!stack[*-1] == 0 {
+            $retval = [ |@!trail ];
+            ++$!count;
+         }
+         if (@!trail < @!stack) { # initialize
+            my $min = @!trail ?? @!trail[*-1] !! 1;
+            @!trail.push: $min;
+         }
+         else { # continue this frame's iteration
+            @!trail[*-1]++;
+         }
+         if (@!trail[*-1] <= @!stack[*-1]) { # "recurse"
+            @!stack.push: @!stack[*-1] - @!trail[*-1];
+         }
+         else { # "return"
+            @!trail.pop;
+            @!stack.pop;
+         }
+      }
+      return $retval;
+   }
+}