From ad5afaa24f905945daec75e9ebcb311d883436f7 Mon Sep 17 00:00:00 2001
From: Simon Proctor <simon.proctor@zpg.co.uk>
Date: Mon, 22 Jul 2019 10:43:34 +0100
Subject: Longest substrings challenge

---
 challenge-018/simon-proctor/perl6/ch-1.p6 | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 challenge-018/simon-proctor/perl6/ch-1.p6

diff --git a/challenge-018/simon-proctor/perl6/ch-1.p6 b/challenge-018/simon-proctor/perl6/ch-1.p6
new file mode 100644
index 0000000000..ee828ecfd1
--- /dev/null
+++ b/challenge-018/simon-proctor/perl6/ch-1.p6
@@ -0,0 +1,23 @@
+#!/usr/bin/env perl6
+
+use v6;
+
+#| Find the longest common sub strings of a list of strings
+sub MAIN ( 
+    *@words where *.elems > 1 #= List of words to compare
+) {
+    my @word-subs = @words.map( &all-substrings );
+    .say for ([(&)] @word-subs).keys.sort( { $^b.codes <=> $^a.codes } ).grep( { state $len = $_.codes; $_.codes == $len });
+}
+
+sub all-substrings( Str $word ) {
+    my $len = $word.codes;
+    my @subs;
+
+    for (1..$len) -> $sub-len {
+        for (0..$len-$sub-len) -> $start {
+            @subs.push( $word.substr($start,$sub-len) );
+        }
+    }
+    return set( @subs );
+}
-- 
cgit