From 6750dc1c85e2796da0b31970e0a64d2585386ac2 Mon Sep 17 00:00:00 2001
From: Jose Luis Perez <jluis@escomposlinux.org>
Date: Wed, 7 Oct 2020 12:26:47 +0200
Subject: base strings 1st iteration

---
 challenge-081/jluis/README       |  1 +
 challenge-081/jluis/perl/ch-1.pl | 53 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 challenge-081/jluis/README
 create mode 100644 challenge-081/jluis/perl/ch-1.pl

diff --git a/challenge-081/jluis/README b/challenge-081/jluis/README
new file mode 100644
index 0000000000..ff80e1d3bd
--- /dev/null
+++ b/challenge-081/jluis/README
@@ -0,0 +1 @@
+Solution by jluis
diff --git a/challenge-081/jluis/perl/ch-1.pl b/challenge-081/jluis/perl/ch-1.pl
new file mode 100644
index 0000000000..8549a26895
--- /dev/null
+++ b/challenge-081/jluis/perl/ch-1.pl
@@ -0,0 +1,53 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+sub base { 
+    # bassed on Abigil's prime number regex	
+    # get all base strings of $_[0] 
+    # a base string is one that concateneted 0 or more times can generate 
+    # the original string
+    my $orig = shift;
+    my @bases;
+    my $length = 1;
+    while (1) {
+        last unless $orig =~ /^(.{$length,}?)\1+$/;
+	push @bases,$1;
+	$length = 1+length($1); 
+    }
+    return (@bases,$orig)
+}
+
+sub format_list {
+	my $out = "("; 
+	while (my $val = shift) {
+	    $out .= '"'.$val.'"';
+	    $out .= ',' if defined @_[0];
+        }
+	return "$out)";
+}
+
+sub common_base {
+    my @A = base(shift);
+    my @B = base(shift);
+    my @result;
+    my $AIndex = 0;
+    my $BIndex = 0;
+    while ($AIndex  <= $#A and $BIndex <= $#B) {
+	   if ($A[$AIndex] eq $B[$BIndex]) {
+		   push @result,$A[$AIndex];
+		   $AIndex += 1;
+		   $BIndex += 1;
+		   next;
+	   }
+           last if length($A[$AIndex]) == length($B[$BIndex]);	   
+           if (length($A[$AIndex]) > length($B[$BIndex])) {
+	           $BIndex  += 1;
+           } else {
+		   $AIndex  += 1;
+	   }	   
+    }
+   return @result;
+}
+CORE::say format_list common_base 'aa'x210,'a'x105;
-- 
cgit