Add polettix's solution to PWC098

4 files changed, 52 insertions, 0 deletions

diff --git a/challenge-098/polettix/blog.txt b/challenge-098/polettix/blog.txt
new file mode 100644
index 0000000000..85d56a733e
--- /dev/null
+++ b/challenge-098/polettix/blog.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2021/02/03/pwc098-readn/
diff --git a/challenge-098/polettix/blog1.txt b/challenge-098/polettix/blog1.txt
new file mode 100644
index 0000000000..d25fb34087
--- /dev/null
+++ b/challenge-098/polettix/blog1.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2021/02/04/pwc098-search-insert-position/
diff --git a/challenge-098/polettix/perl/ch-1.pl b/challenge-098/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..e481a2e81b
--- /dev/null
+++ b/challenge-098/polettix/perl/ch-1.pl
@@ -0,0 +1,26 @@
+#!/usr/bin/env perl
+use 5.024;
+use warnings;
+use experimental qw< postderef signatures >;
+no warnings qw< experimental::postderef experimental::signatures >;
+use Fcntl qw< O_RDONLY SEEK_SET >;
+
+sub readN ($FILE, $number) {
+   state $at = {};
+   sysopen my $fh, $FILE, O_RDONLY or die "sysopen('$FILE'): $!\n";
+   sysseek $fh, $at->{$FILE} // 0, SEEK_SET;
+   my $retval = '';
+   my $n = sysread $fh, $retval, $number;
+   close $fh or die "close('$FILE'): $!\n";
+   die "sysread($FILE) \@$number: $!\n"  if ! defined $n;
+   $at->{$FILE} += $n;
+   return $retval;
+}
+
+my $highlight = "\e[1;97;45m"; my $reset = "\e[0m";
+my $file = shift || __FILE__;
+my @numbers = @ARGV ? @ARGV : qw< 4 5 2 >;
+for my $n (@numbers) {
+   my $chunk = readN($file, $n);
+   say "got $n: $highlight$chunk$reset";
+}
diff --git a/challenge-098/polettix/perl/ch-2.pl b/challenge-098/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..7ed0201d3a
--- /dev/null
+++ b/challenge-098/polettix/perl/ch-2.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/env perl
+use 5.024;
+use warnings;
+use experimental qw< postderef signatures >;
+no warnings qw< experimental::postderef experimental::signatures >;
+
+sub search_insert_position ($aref, $new_item) {
+   my ($lo, $hi, $i) = (0, $aref->$#*, undef);
+   while ($lo <= $hi) {
+      $i = int(($lo + $hi) / 2);
+      my $item = $aref->[$i];
+      if ($new_item == $item)   { return $i }
+      elsif ($new_item < $item) { $hi = $i }
+      else                      { $lo = $i }
+      last if ($hi - $lo) <= 1;
+   }
+   splice $aref->@*, $i, 0, $new_item;
+   return $i;
+}
+
+my $N = @ARGV ? shift @ARGV : 3;
+my @N = @ARGV ? @ARGV : qw< 1 2 3 4 >;
+my $i = search_insert_position(\@N, $N);
+say "$i -> (@N)";