Merge pull request #7246 from jacoby/master

jacoby finishes Ch 195

2 files changed, 55 insertions, 0 deletions

diff --git a/challenge-195/dave-jacoby/perl/ch-1.pl b/challenge-195/dave-jacoby/perl/ch-1.pl
new file mode 100644
index 0000000000..189613873e
--- /dev/null
+++ b/challenge-195/dave-jacoby/perl/ch-1.pl
@@ -0,0 +1,26 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ fc say postderef signatures state };
+
+my @examples = ( 15, 35 );
+for my $n (@examples) {
+    my $o = special_list($n);
+    say <<"END";
+    Input:  \$n = $n
+    Output: $o
+END
+}
+
+sub special_list ( $n ) {
+    return scalar grep { is_special($_) } 1 .. $n;
+}
+
+sub is_special ( $n ) {
+    my %hash;
+    for my $i ( split //, $n ) {
+        return 0 if ++$hash{$i} > 1;
+    }
+    return 1;
+}
diff --git a/challenge-195/dave-jacoby/perl/ch-2.pl b/challenge-195/dave-jacoby/perl/ch-2.pl
new file mode 100644
index 0000000000..9a704a2c63
--- /dev/null
+++ b/challenge-195/dave-jacoby/perl/ch-2.pl
@@ -0,0 +1,29 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+use List::Util qw{ min max };
+
+my @examples = ( [ 1, 1, 2, 6, 2 ], [ 1, 3, 5, 7 ], [ 6, 4, 4, 6, 1 ] );
+
+for my $e (@examples) {
+    my $list = join ',', $e->@*;
+    my $o    = most_frequent_even( $e->@* );
+    say <<"END";
+    Input:  \@list = $list
+    Output: $o
+END
+}
+
+sub most_frequent_even( @list ) {
+    my %hash;
+    map { $hash{$_}++ } grep { 0 == $_ % 2 } @list;
+    if ( scalar keys %hash ) {
+        my $max = max values %hash;
+        return min grep { $hash{$_} == $max } keys %hash;
+    }
+    return -1;
+}
+