Add polettix's solution to challenge-178

6 files changed, 253 insertions, 0 deletions

diff --git a/challenge-178/polettix/blog.txt b/challenge-178/polettix/blog.txt
new file mode 100644
index 0000000000..66cb445e10
--- /dev/null
+++ b/challenge-178/polettix/blog.txt
@@ -0,0 +1 @@
+https://etoobusy.polettix.it/2022/08/17/pwc178-quater-imaginary-base/
diff --git a/challenge-178/polettix/blog1.txt b/challenge-178/polettix/blog1.txt
new file mode 100644
index 0000000000..9de560a0c8
--- /dev/null
+++ b/challenge-178/polettix/blog1.txt
@@ -0,0 +1 @@
+https://etoobusy.polettix.it/2022/08/18/pwc178-business-date/
diff --git a/challenge-178/polettix/perl/ch-1.pl b/challenge-178/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..965330c0fa
--- /dev/null
+++ b/challenge-178/polettix/perl/ch-1.pl
@@ -0,0 +1,45 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+say to_m4i(shift // 4);
+
+sub to_m4i ($x) {
+   my ($real, $img) = parse_complex($x);
+   $real = join('0', split m{}mxs, b10_to_bm($real, -4)) || 0;
+   if ($img) {
+      $img  = join('0', split m{}mxs, b10_to_bm(-2 * $img, -4));
+      my $after = substr $img, -1, 1, '';
+      $real += $img if $img;
+      $real .= '.' . $after if $after;
+   }
+   return $real;
+}
+
+sub b10_to_bm ($x, $m) {
+   my @digits;
+   while ($x) {
+      my $rem = $x % $m;
+      $x = (($x - $rem) / $m);
+      ($rem, $x) = ($rem - $m, $x + 1) if $rem < 0;
+      unshift @digits, $rem;
+   }
+   return join '', @digits;
+}
+
+sub parse_complex ($x) {
+   $x =~ m{
+      \A\s*(?:
+            (?<real> 0 | -?[1-9]\d*)
+         |  (?<real> 0 | -?[1-9]\d*) \s* (?<img> [-+]  (?:[1-9]\d*|))i
+         |                               (?<img> [-+]? (?:[1-9]\d*|))i
+      )\s*\z
+   }mxs;
+   my $real = $+{real} // 0;
+   my $img = $+{img} // 0;
+   $img = 1 if $img eq '' || $img eq '+';
+   $img = -1 if $img eq '-';
+   return ($real, $img);
+}
diff --git a/challenge-178/polettix/perl/ch-2.pl b/challenge-178/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..b4a2b45064
--- /dev/null
+++ b/challenge-178/polettix/perl/ch-2.pl
@@ -0,0 +1,75 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+use Time::Local 'timegm';
+
+my $ts       = shift // '2022-08-01 10:30';
+my $duration = shift // 4;
+say add_bh($ts, $duration);
+
+sub parse_datetime ($dt) {
+   my $error = "invalid input timestamp <$dt>\n";
+   my ($y, $m, $d, $H, $M) = $dt =~ m{
+      \A (\d+) - (\d\d) - (\d\d) \  (\d\d):(\d\d) \z
+   }mxs or die $error;
+   die $error unless eval {
+      timegm(0, $M, $H, $d, $m - 1, $y);
+      1;
+   };
+   return [ $y, $m, $d, $H, $M ];
+}
+
+sub add_bh ($timestamp, $duration) {
+   state $sod_min =  9 * 60;
+   state $eod_min = 18 * 60;
+   my $duration_min = int($duration * 60); # in minutes, rounded down
+
+   my $dt = parse_datetime($timestamp);
+
+   # cope with the possibility that the provided timestamp is
+   # *outside* the allowed range, move to the beginning of the
+   # next business day
+   $dt = next_business_day_start($dt) unless is_in_business($dt);
+   my $start_min = $dt->[3] * 60 + $dt->[4];
+
+   while ($duration_min > 0) {
+      my $available_min = $eod_min - $start_min;
+      if ($duration_min >= $available_min) {
+         $dt = next_business_day_start($dt);
+         $duration_min -= $available_min;
+         $start_min = $sod_min;
+      }
+      else { # we're in the very day!
+         my $stop_min = $start_min + $duration_min;
+         $dt->[4] = my $M = $stop_min % 60;
+         $dt->[3] = ($stop_min - $M) / 60;
+         $duration_min = 0;
+      }
+   }
+
+   return sprintf '%04d-%02d-%02d %02d:%02d', $dt->@*;
+}
+
+sub is_in_business ($dt) {
+   my ($y, $m, $d, $H, $M) = $dt->@*;
+   return if $H < 9 || $H > 17; # 18:00 is out ;)
+   my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) =
+     gmtime(timegm(0, $M, $H, $d, $m - 1, $y));
+   return (0 < $wday && $wday < 6);
+} ## end sub is_in_business ($dt)
+
+sub next_business_day_start ($dt) {
+   state $day_s = 24 * 60 * 60;
+   my ($y, $m, $d) = $dt->@*;
+   while ('necessary') {
+      my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) =
+         gmtime($day_s + timegm(0, 30, 12, $d, $m - 1, $y));
+      $year += 1900;
+      ++$mon;
+      return [$year, $mon, $mday, 9, 0]
+         if 0 < $wday && $wday < 6;
+      ($y, $m, $d) = ($year, $mon, $mday);
+   }
+}
diff --git a/challenge-178/polettix/raku/ch-1.raku b/challenge-178/polettix/raku/ch-1.raku
new file mode 100644
index 0000000000..a9968c0e0a
--- /dev/null
+++ b/challenge-178/polettix/raku/ch-1.raku
@@ -0,0 +1,63 @@
+#!/usr/bin/env raku
+use v6;
+
+sub MAIN (Str:D() $x) { put to-m4i($x) }
+
+sub to-m4i (Complex:D() $cx) {
+   my $real = b10-to-bm($cx.re.Int, -4).comb.join('0') || 0;
+   my $img  = b10-to-bm(-2 * $cx.im.Int, -4).comb.join('0');
+   if $img.chars {
+      my $after = $img.substr(*-1, 1);
+      $img.substr-rw(*-1, 1) = '';
+      $real += $img if $img.elems;
+      $real ~= '.' ~ $after if $after > 0;
+   }
+   return $real;
+}
+
+multi sub b10-to-bm (Int:D $x is copy, Int:D $m where * < 0 --> Str) {
+   my @digits;
+   while $x {
+      my $rem = $x % $m;
+      $x = (($x - $rem) / $m).Int;
+      ($rem, $x) = $rem - $m, $x + 1 if $rem < 0;
+      @digits.unshift: $rem;
+   }
+   return @digits.join('');
+}
+
+=finish
+
+multi sub b10-to-bm (Int:D $x is copy, Int:D $m where * > 0 --> Str) {
+   my @digits;
+   my $sign = '';
+   ($sign, $x) = ('-', $x.abs) if $x < 0;
+   while $x {
+      @digits.unshift: my $rem = $x % $m;
+      $x = (($x - $rem) / $m).Int;
+   }
+   @digits.unshift: $sign;
+   return @digits.join('');
+}
+
+sub bm-to-b10 (Str:D $x is copy, Int:D $m --> Int) {
+   my $sign = 1;
+   my @digits = $x.comb;
+   if ($m > 0 && @digits[0] eq '-') {
+      @digits.shift;
+      $sign = -1;
+   }
+
+   state %weight_for;
+   if ! %weight_for.elems {
+      %weight_for{$_} = .Int for 0 .. 9;
+      %weight_for{$_} = 10 + .ord - 'a'.ord for 'a' .. 'z';
+      %weight_for{$_} = 10 + .ord - 'A'.ord for 'A' .. 'Z';
+   }
+
+   my $retval = 0;
+   for @digits -> $digit {
+      $retval = $retval * $m + %weight_for{$digit};
+   }
+   return $sign * $retval;
+}
diff --git a/challenge-178/polettix/raku/ch-2.raku b/challenge-178/polettix/raku/ch-2.raku
new file mode 100644
index 0000000000..7d21386572
--- /dev/null
+++ b/challenge-178/polettix/raku/ch-2.raku
@@ -0,0 +1,68 @@
+#!/usr/bin/env raku
+use v6;
+
+sub MAIN ($ts = '2022-08-01 10:30', $duration = 4) {
+   put add-bh($ts, $duration);
+}
+
+sub parse_datetime ($dt) {
+   my $error = "invalid input timestamp <$dt>\n";
+   my $match = $dt ~~ /
+      ^ (\d+) '-' (\d\d) '-' (\d\d) ' ' (\d\d) ':' (\d\d) $
+   / or die $error;
+   my ($y, $m, $d, $H, $M) = $match[0..4].map({0 + $_});
+   try {
+      CATCH {
+         default { die $error }
+      }
+      return DateTime.new(year => $y, month => $m, day => $d,
+         hour => $H, minute => $M);
+   }
+}
+
+sub is-in-business ($dt) {
+   return (
+      (9 <= $dt.hour < 18) # 18:00 is out ;)
+      &&  (1 <= $dt.day-of-week <= 5)
+   );
+} ## end sub is_in_business ($dt)
+
+sub next-business-day-start ($dt is copy) {
+   loop {
+      $dt = $dt.clone(hour => 9, minute => 0).later(day => 1);
+      return $dt if (1 <= $dt.day-of-week <= 5);
+   }
+}
+
+sub add-bh ($timestamp, $duration) {
+   state $sod_min =  9 * 60;
+   state $eod_min = 18 * 60;
+   my $duration_min = ($duration * 60).Int; # in minutes, rounded down
+
+   my $dt = parse_datetime($timestamp);
+
+   # cope with the possibility that the provided timestamp is
+   # *outside* the allowed range, move to the beginning of the
+   # next business day
+   $dt = next-business-day-start($dt) unless is-in-business($dt);
+   my $start_min = $dt.hour * 60 + $dt.minute;
+
+   while $duration_min > 0 {
+      my $available_min = $eod_min - $start_min;
+      if ($duration_min >= $available_min) {
+         $dt = next-business-day-start($dt);
+         $duration_min -= $available_min;
+         $start_min = $sod_min;
+      }
+      else { # we're in the very day!
+         my $stop_min = $start_min + $duration_min;
+         my $M = $stop_min % 60;
+         my $H = ($stop_min - $M) / 60;
+         $dt = $dt.clone(hour => $H, minute => $M);
+         $duration_min = 0;
+      }
+   }
+
+   return '%04d-%02d-%02d %02d:%02d'.sprintf(
+      $dt.year, $dt.month, $dt.day, $dt.hour, $dt.minute);
+}