Merge pull request #9306 from kjetillll/challenge-248-kjetillll

https://theweeklychallenge.org/blog/perl-weekly-challenge-248/

2 files changed, 64 insertions, 0 deletions

diff --git a/challenge-248/kjetillll/perl/ch-1.pl b/challenge-248/kjetillll/perl/ch-1.pl
new file mode 100644
index 0000000000..217119d85c
--- /dev/null
+++ b/challenge-248/kjetillll/perl/ch-1.pl
@@ -0,0 +1,15 @@
+#!/usr/bin/perl
+#https://theweeklychallenge.org/blog/perl-weekly-challenge-248/
+use strict; use warnings;
+use Test::More tests=>2;
+is_deeply [ SD("loveleetcode", "e") ] => [ 3,2,1,0,1,0,0,1,2,2,1,0 ];
+is_deeply [ SD("aaab",         "b") ] => [ 3,2,1,0 ];
+
+sub SD {
+    my($str,$char)=@_;
+    my @s = split//, $str;
+    my $dist   = sub { my $d = 9e9; map $_ eq $char ? ($d=0) : ++$d, @_ };
+    my @after  =         &$dist(         @s );
+    my @before = reverse &$dist( reverse @s );
+    map $after[$_] < $before[$_] ? $after[$_] : $before[$_], 0 .. $#s;
+}
diff --git a/challenge-248/kjetillll/perl/ch-2.pl b/challenge-248/kjetillll/perl/ch-2.pl
new file mode 100644
index 0000000000..a24488074e
--- /dev/null
+++ b/challenge-248/kjetillll/perl/ch-2.pl
@@ -0,0 +1,49 @@
+#!/usr/bin/perl
+#https://theweeklychallenge.org/blog/perl-weekly-challenge-248/
+use strict; use warnings; use Test::More tests=>2;
+
+is_deeply [ sum2x2(
+                [1,  2,  3,  4],
+                [5,  6,  7,  8],
+                [9, 10, 11, 12] )
+          ] => [
+                [14, 18, 22],
+                [30, 34, 38]
+          ];
+
+is_deeply [ sum2x2(
+                [1, 0, 0, 0],
+                [0, 1, 0, 0],
+                [0, 0, 1, 0],
+                [0, 0, 0, 1] )
+          ] => [
+                [2, 1, 0],
+                [1, 2, 1],
+                [0, 1, 2]
+          ];
+
+sub slide_matrix (&$$$) {
+    my($sub, $w, $h, $m) = @_;
+    for my $i ( 0 ..  @$m - $h ) {
+        for my $j ( 0 .. @{ $$m[0] } - $w ){
+            my @sm;
+            for my $x ( 0 .. $w-1 ) {
+                for my $y ( 0 .. $h-1 ) {
+                    $sm[$x][$y] = $$m[$i+$x][$j+$y]
+                }
+            }
+            &$sub(\@sm,$i,$j)
+        }
+    }
+}
+
+sub sum2x2 {
+    my @matrix = @_;
+    my @result;
+    slide_matrix {
+        my($subm, $i, $j) = @_;
+        push @{ $result[$i] //= [] },  $$subm[0][0] + $$subm[0][1]
+                                     + $$subm[1][0] + $$subm[1][1];
+    } 2, 2, \@matrix;
+    @result
+}