https://theweeklychallenge.org/blog/perl-weekly-challenge-345/

2 files changed, 37 insertions, 0 deletions

diff --git a/challenge-345/kjetillll/perl/ch-1.pl b/challenge-345/kjetillll/perl/ch-1.pl
new file mode 100644
index 0000000000..9ef8dece4a
--- /dev/null
+++ b/challenge-345/kjetillll/perl/ch-1.pl
@@ -0,0 +1,9 @@
+sub peaks {
+    grep { ( $_[$_-1] // -Inf ) < $_[$_] > ( $_[$_+1] // -Inf ) } 0 .. $#_
+}
+use Test::More tests => 5;
+is_deeply [ peaks(1, 3, 2)             ],  [1];
+is_deeply [ peaks(2, 4, 6, 5, 3)       ],  [2];
+is_deeply [ peaks(1, 2, 3, 2, 4, 1)    ],  [2, 4];
+is_deeply [ peaks(5, 3, 1)             ],  [0];
+is_deeply [ peaks(1, 5, 1, 5, 1, 5, 1) ],  [1, 3, 5];
diff --git a/challenge-345/kjetillll/perl/ch-2.pl b/challenge-345/kjetillll/perl/ch-2.pl
new file mode 100644
index 0000000000..6d514681c1
--- /dev/null
+++ b/challenge-345/kjetillll/perl/ch-2.pl
@@ -0,0 +1,28 @@
+sub f_straightforward {
+    my($x, @seen, @ans) = (0);
+    for( @_ ){
+        if ( $_ >= 0 ) {
+            unshift @seen, $_;
+            $x = 0;
+        }
+        else {
+            push @ans, $x < @seen ? $seen[$x] : -1;
+            $x++
+        }
+    }
+    @ans
+}
+
+sub f_kinda_functional {
+    my($x, @seen) = (0);
+    grep defined, map $_ > 0 && [$x=0, unshift @seen, $_] ? undef : $x++ < @seen ? $seen[$x-1] : -1, @_
+}
+
+use Test::More tests => 2 * 5;
+for my $f ( \&f_straightforward, \&f_kinda_functional ){
+    is_deeply [ &$f(5, -1, -1)              ],  [ 5, -1      ];
+    is_deeply [ &$f(3, 7, -1, -1, -1)       ],  [ 7, 3, -1   ];
+    is_deeply [ &$f(2, -1, 4, -1, -1)       ],  [ 2, 4, 2    ];
+    is_deeply [ &$f(10, 20, -1, 30, -1, -1) ],  [ 20, 30, 20 ];
+    is_deeply [ &$f(-1, -1, 5, -1)          ],  [ -1, -1, 5  ];
+}