From 1c40638f33d2ef5ce68fc54e6395b6534e4eee81 Mon Sep 17 00:00:00 2001
From: Flavio Poletti <flavio@polettix.it>
Date: Thu, 14 Apr 2022 07:50:47 +0200
Subject: Add polettix's solution to challenge-160

---
 challenge-160/polettix/blog.txt       |  1 +
 challenge-160/polettix/blog1.txt      |  1 +
 challenge-160/polettix/perl/ch-1.pl   | 22 ++++++++++++++++++++++
 challenge-160/polettix/perl/ch-2.pl   | 16 ++++++++++++++++
 challenge-160/polettix/raku/ch-1.raku | 17 +++++++++++++++++
 challenge-160/polettix/raku/ch-2.raku | 11 +++++++++++
 6 files changed, 68 insertions(+)
 create mode 100644 challenge-160/polettix/blog.txt
 create mode 100644 challenge-160/polettix/blog1.txt
 create mode 100644 challenge-160/polettix/perl/ch-1.pl
 create mode 100644 challenge-160/polettix/perl/ch-2.pl
 create mode 100644 challenge-160/polettix/raku/ch-1.raku
 create mode 100644 challenge-160/polettix/raku/ch-2.raku

diff --git a/challenge-160/polettix/blog.txt b/challenge-160/polettix/blog.txt
new file mode 100644
index 0000000000..e674a137d1
--- /dev/null
+++ b/challenge-160/polettix/blog.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/04/12/pwc160-four-is-magic/
diff --git a/challenge-160/polettix/blog1.txt b/challenge-160/polettix/blog1.txt
new file mode 100644
index 0000000000..9698daf7f4
--- /dev/null
+++ b/challenge-160/polettix/blog1.txt
@@ -0,0 +1 @@
+https://github.polettix.it/ETOOBUSY/2022/04/13/pwc160-equilibrium-index/
diff --git a/challenge-160/polettix/perl/ch-1.pl b/challenge-160/polettix/perl/ch-1.pl
new file mode 100644
index 0000000000..01407eee11
--- /dev/null
+++ b/challenge-160/polettix/perl/ch-1.pl
@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+my $n = shift // 7;
+say four_is_magic($n);
+
+sub four_is_magic ($n) {
+   state $ints = [qw< zero one two three four five six seven eight nine >];
+   my $current = $ints->[$n];
+   my @seq;
+   while ($n != 4) {
+      $n = length $current;
+      (my $previous, $current) = ($current, $ints->[$n]);
+      push @seq, "$previous is $current";
+   }
+   push @seq, 'four is magic.';
+   $seq[0] = ucfirst $seq[0];
+   return join ', ', @seq;
+}
diff --git a/challenge-160/polettix/perl/ch-2.pl b/challenge-160/polettix/perl/ch-2.pl
new file mode 100644
index 0000000000..2fcb0b5ea7
--- /dev/null
+++ b/challenge-160/polettix/perl/ch-2.pl
@@ -0,0 +1,16 @@
+#!/usr/bin/env perl
+use v5.24;
+use warnings;
+use experimental 'signatures';
+no warnings 'experimental::signatures';
+
+my @n = @ARGV ? @ARGV : (1, 3, 5, 7, 9);
+say equilibrium_index(@n);
+
+sub equilibrium_index (@n) {
+   my $i_lo = 0;
+   my $i_hi = $#n;
+   my $diff = 0;
+   $diff += ($diff <= 0 ? $n[$i_lo++] : -$n[$i_hi--]) while $i_lo < $i_hi;
+   return @n && $diff == 0 ? $i_lo : -1;
+}
diff --git a/challenge-160/polettix/raku/ch-1.raku b/challenge-160/polettix/raku/ch-1.raku
new file mode 100644
index 0000000000..4423d6e12f
--- /dev/null
+++ b/challenge-160/polettix/raku/ch-1.raku
@@ -0,0 +1,17 @@
+#!/usr/bin/env raku
+use v6;
+sub MAIN (Int:D $n where 0 < * < 10 = 5) { put four-is-magic($n); }
+
+sub four-is-magic (Int:D $n is copy where 0 < * < 10) {
+   state @ints = <zero one two three four five six seven eight nine >;
+   my $current = @ints[$n];
+   my @seq = gather while $n != 4 {
+      $n = $current.chars;
+      my $next = @ints[$n];
+      take "$current is $next";
+      $current = $next;
+   };
+   @seq.push: 'four is magic.';
+   @seq[0] = @seq[0].tclc;
+   return @seq.join(', ');
+}
diff --git a/challenge-160/polettix/raku/ch-2.raku b/challenge-160/polettix/raku/ch-2.raku
new file mode 100644
index 0000000000..4bdc0c1c3d
--- /dev/null
+++ b/challenge-160/polettix/raku/ch-2.raku
@@ -0,0 +1,11 @@
+#!/usr/bin/env raku
+use v6;
+sub MAIN (*@args) { put equilibrium-index(@args) }
+
+sub equilibrium-index (@n) {
+   my $i_lo = 0;
+   my $i_hi = @n.end;
+   my $diff = 0;
+   $diff += ($diff <= 0 ?? @n[$i_lo++] !! -@n[$i_hi--]) while $i_lo < $i_hi;
+   return @n && $diff == 0 ?? $i_lo !! -1;
+}
-- 
cgit