#202 DAJ

2 files changed, 97 insertions, 0 deletions

diff --git a/challenge-202/dave-jacoby/perl/ch-1.pl b/challenge-202/dave-jacoby/perl/ch-1.pl
new file mode 100644
index 0000000000..d64974b1cd
--- /dev/null
+++ b/challenge-202/dave-jacoby/perl/ch-1.pl
@@ -0,0 +1,40 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+my @examples = (
+
+    [ 1, 5, 3, 6 ],
+    [ 2, 6, 3, 5 ],
+    [ 1, 2, 3, 4 ],
+    [ 2, 3, 5, 7 ],
+    [ 2, 3, 4, 7, 9, 11, 13 ],
+
+);
+
+for my $e (@examples) {
+    my $list = join ',', $e->@*;
+    my $out  = consecutive_odds( $e->@* );
+    say <<"END";
+    Input:  \@array = ($list)
+    Output: $out
+END
+}
+
+sub consecutive_odds ( @array ) {
+    my $max = -3 + scalar @array;
+OUTER: for my $i ( 0 .. $max ) {
+        for my $j ( 0 .. 2 ) {
+            my $n = $array[ $i + $j ];
+            next OUTER if !is_odd($n);
+            return 1   if $j == 2;
+        }
+    }
+    return 0;
+}
+
+sub is_odd ( $n ) {
+    return $n % 2 ? 1 : 0;
+}
diff --git a/challenge-202/dave-jacoby/perl/ch-2.pl b/challenge-202/dave-jacoby/perl/ch-2.pl
new file mode 100644
index 0000000000..cbe4eebfa7
--- /dev/null
+++ b/challenge-202/dave-jacoby/perl/ch-2.pl
@@ -0,0 +1,57 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use experimental qw{ say postderef signatures state };
+
+use List::Util qw{ sum0 uniq };
+
+my @examples = (
+
+    [ 1, 5, 5,  2, 8 ],
+    [ 2, 6, 8,  5 ],
+    [ 9, 8, 13, 13, 2, 2, 15, 17 ],
+    [ 2, 1, 2,  1,  3 ],
+    [ 1, 3, 3,  2,  1, 2, 3, 3, 2 ],
+);
+
+for my $e (@examples) {
+    my $example = join ', ', $e->@*;
+    my @valley  = widest_valley( $e->@* );
+    my $valley  = join ', ', @valley;
+    say <<"END";
+    Input:  \$n = $example
+    Output: $valley
+END
+}
+
+sub widest_valley ( @array ) {
+    my @output;
+    my $end = -1 + scalar @array;
+
+OUTER: for my $i ( 0 .. $end ) {
+
+        # 0 = non-increasing, 1 = non-decreasing
+        my $state = 0;
+        my @local;
+        for my $j ( $i .. $end ) {
+            my $n = $array[$j];
+
+            # descending
+            if ( $state == 0 && scalar @local && $n > $local[-1] ) {
+                $state = 1;
+            }
+            elsif ( $state == 1 && $n < $local[-1] ) {
+                next OUTER;
+            }
+            push @local, $n;
+            my @copy = @local;
+            push @output, \@copy if scalar @copy > 2;
+        }
+    }
+
+    @output = sort { scalar $b->@* <=> scalar $a->@* } @output;
+    return () unless scalar @output;
+    return $output[0]->@*;
+}
+