Merge pull request #7248 from jeanluc2020/jeanluc-195

Add jeanluc2020's solution to challenge 195.

2 files changed, 61 insertions, 0 deletions

diff --git a/challenge-195/jeanluc2020/perl/ch-1.pl b/challenge-195/jeanluc2020/perl/ch-1.pl
new file mode 100755
index 0000000000..79573aa3fc
--- /dev/null
+++ b/challenge-195/jeanluc2020/perl/ch-1.pl
@@ -0,0 +1,31 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+foreach my $input (1..40) {
+   print "Input $input, output " . count_specials($input) . "\n";
+}
+
+sub count_specials {
+   my $number = shift;
+   my $specials = 0;
+   foreach my $i (1..$number) {
+      $specials += is_special($i);
+   }
+   return $specials;
+}
+
+sub is_special {
+   my $number = shift;
+   my $map;
+   # count all digits by adding 1 to the corresponding key in %$map for each digit
+   # the count is the value
+   map { $map->{$_}++ } split //, $number;
+   # sort values descending
+   my @values = reverse sort { $a <=> $b } values %$map;
+   # if the first element is 1, the number is special
+   if($values[0] == 1) {
+      return 1;
+   }
+   return 0;
+}
diff --git a/challenge-195/jeanluc2020/perl/ch-2.pl b/challenge-195/jeanluc2020/perl/ch-2.pl
new file mode 100755
index 0000000000..ec92ca072b
--- /dev/null
+++ b/challenge-195/jeanluc2020/perl/ch-2.pl
@@ -0,0 +1,30 @@
+#!/usr/bin/perl
+
+my @list = (1,1,2,6,2);
+print "(" . join(",", @list) . ") => " . smallest_even_integer(@list) . "\n";
+@list = (1,3,5,7);
+print "(" . join(",", @list) . ") => " . smallest_even_integer(@list) . "\n";
+@list = (6,4,4,6,1);
+print "(" . join(",", @list) . ") => " . smallest_even_integer(@list) . "\n";
+
+sub smallest_even_integer {
+   # we need only even numbers
+   my @list = only_even(@_);
+   return -1 unless @list; # no even numbers found
+   my $map;
+   # count each number in %$map, key is the number, value its count
+   map { $map->{$_}++ } @list;
+   # sort @list by the count for each number descending
+   # if that's equal sort by the number ascending
+   my @sorted = sort { $map->{$b} <=> $map->{$a} || $a <=> $b } @list;
+   # solution is in the first element of the sorted array
+   return $sorted[0];
+}
+
+sub only_even {
+   my @result = ();
+   foreach my $elem (@_) {
+      push @result,$elem unless $elem % 2;
+   }
+   return @result;
+}