From 090af051b19abda6d8c10b7cafe0eb8a119bd9ec Mon Sep 17 00:00:00 2001
From: LapVeesh <rabbiveesh@gmail.com>
Date: Sun, 11 Aug 2019 23:46:33 +0300
Subject: Added answers to challenge 20. Many regexes

---
 challenge-020/veesh-goldman/blog.txt          |  1 +
 challenge-020/veesh-goldman/perl5/ch-01.sh    |  3 +++
 challenge-020/veesh-goldman/perl5/ch-02.pl    | 24 ++++++++++++++++++++++++
 challenge-020/veesh-goldman/perl5/t/factors.t | 17 +++++++++++++++++
 4 files changed, 45 insertions(+)
 create mode 100644 challenge-020/veesh-goldman/blog.txt
 create mode 100755 challenge-020/veesh-goldman/perl5/ch-01.sh
 create mode 100755 challenge-020/veesh-goldman/perl5/ch-02.pl
 create mode 100644 challenge-020/veesh-goldman/perl5/t/factors.t

diff --git a/challenge-020/veesh-goldman/blog.txt b/challenge-020/veesh-goldman/blog.txt
new file mode 100644
index 0000000000..b66597e216
--- /dev/null
+++ b/challenge-020/veesh-goldman/blog.txt
@@ -0,0 +1 @@
+http://blogs.perl.org/users/veesh/2019/08/solving-two-problems.html
diff --git a/challenge-020/veesh-goldman/perl5/ch-01.sh b/challenge-020/veesh-goldman/perl5/ch-01.sh
new file mode 100755
index 0000000000..14c1ada7e3
--- /dev/null
+++ b/challenge-020/veesh-goldman/perl5/ch-01.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+perl -pE'split / /, s/(.) \g1*/$& /gx'
diff --git a/challenge-020/veesh-goldman/perl5/ch-02.pl b/challenge-020/veesh-goldman/perl5/ch-02.pl
new file mode 100755
index 0000000000..e5ef309883
--- /dev/null
+++ b/challenge-020/veesh-goldman/perl5/ch-02.pl
@@ -0,0 +1,24 @@
+#! /usr/bin/env perl
+use v5.22;
+
+sub sum_of_proper_divisors {
+  #start with one, because that is always a divisor
+  my $sum = 1;
+  (1 x shift) =~ /^ (..+) \g1+ $ (?{ $sum += length $1 }) ./xg;
+  return $sum
+}
+
+sub has_amicable {
+  my $start = shift;
+  #sometimes the sum of the divisors IS the number. But that's not amicable
+  return 0 if sum_of_proper_divisors($start) == $start;
+  return $start == sum_of_proper_divisors( sum_of_proper_divisors($start) )
+}
+
+
+my $num;
+while (1) {
+  last if has_amicable(++$num);
+}
+
+say "$num, ${\sum_of_proper_divisors($num)} is your pair"
diff --git a/challenge-020/veesh-goldman/perl5/t/factors.t b/challenge-020/veesh-goldman/perl5/t/factors.t
new file mode 100644
index 0000000000..7467115a68
--- /dev/null
+++ b/challenge-020/veesh-goldman/perl5/t/factors.t
@@ -0,0 +1,17 @@
+use Test2::V0;
+
+
+sub sum_factors {
+  my $expansion = 1 x shift;
+  my $sum = 1;
+  $expansion =~ /^(..+) \g1+ $ (?{ $sum += length $1 }) ./xg;
+
+  return $sum
+}
+
+is sum_factors(4), 3;
+is sum_factors(220), 284;
+is sum_factors(284), 220;
+
+
+done_testing;
-- 
cgit 


From d60696fd5015f0de3f3d80f4f183ccfe681c4092 Mon Sep 17 00:00:00 2001
From: LapVeesh <rabbiveesh@gmail.com>
Date: Sun, 11 Aug 2019 23:57:34 +0300
Subject: Refactored a drop

---
 challenge-020/veesh-goldman/perl5/ch-02.pl | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/challenge-020/veesh-goldman/perl5/ch-02.pl b/challenge-020/veesh-goldman/perl5/ch-02.pl
index e5ef309883..31c6dedd42 100755
--- a/challenge-020/veesh-goldman/perl5/ch-02.pl
+++ b/challenge-020/veesh-goldman/perl5/ch-02.pl
@@ -10,9 +10,10 @@ sub sum_of_proper_divisors {
 
 sub has_amicable {
   my $start = shift;
+  my $pair = sum_of_proper_divisors($start);
   #sometimes the sum of the divisors IS the number. But that's not amicable
-  return 0 if sum_of_proper_divisors($start) == $start;
-  return $start == sum_of_proper_divisors( sum_of_proper_divisors($start) )
+  return 0 if $pair == $start;
+  return $start == sum_of_proper_divisors $pair;
 }
 
 
-- 
cgit