From 4b6202a6507cb1e1e3854fa643fc25714dc930a2 Mon Sep 17 00:00:00 2001
From: Walt Mankowski <waltman@pobox.com>
Date: Tue, 6 Oct 2020 19:34:55 -0400
Subject: perl solution to challenge 81 task 1

---
 challenge-081/walt-mankowski/perl/ch-1.pl | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 challenge-081/walt-mankowski/perl/ch-1.pl

diff --git a/challenge-081/walt-mankowski/perl/ch-1.pl b/challenge-081/walt-mankowski/perl/ch-1.pl
new file mode 100644
index 0000000000..9a91c9d8db
--- /dev/null
+++ b/challenge-081/walt-mankowski/perl/ch-1.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+use feature qw(:5.32);
+use experimental qw(signatures);
+use List::Util qw(min);
+
+# You are given 2 strings, $A and $B.
+#
+# Write a script to find out common base strings in $A and $B.
+#
+#     A substring of a string $S is called base string if repeated
+#     concatenation of the substring results in the string.
+
+my ($A, $B) = @ARGV;
+my $max_base_len = min(length($A), length($B));
+
+for my $i (1 .. $max_base_len) {
+    if (is_base(substr($A, 0, $i), $A) && is_base(substr($B, 0, $i), $B)) {
+        say substr($A, 0, $i);
+    }
+}
+
+sub is_base($prefix, $s) {
+    my $cnt = length($s) / length($prefix);
+    return $prefix x $cnt eq $s;
+}
+
-- 
cgit