From 72733d3f1f0feb438d74edbca4073bf8874b9345 Mon Sep 17 00:00:00 2001
From: James Smith <js5@sanger.ac.uk>
Date: Tue, 9 May 2023 00:10:01 +0100
Subject: Create ch-2.pl

---
 challenge-216/james-smith/perl/ch-2.pl | 58 ++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 challenge-216/james-smith/perl/ch-2.pl

diff --git a/challenge-216/james-smith/perl/ch-2.pl b/challenge-216/james-smith/perl/ch-2.pl
new file mode 100644
index 0000000000..62fa4d7a69
--- /dev/null
+++ b/challenge-216/james-smith/perl/ch-2.pl
@@ -0,0 +1,58 @@
+#!/usr/local/bin/perl
+
+use strict;
+use warnings;
+use feature qw(say);
+use Test::More;
+use Benchmark qw(cmpthese);
+
+my @TESTS = (
+ [ [qw(peon          perl raku    python)], 2 ],
+ [ [qw(goat          love hate    angry )], 3 ],
+ [ [qw(accommodation come nation  delta )], 4 ],
+ [ [qw(accommodation come country delta )], 0 ],
+);
+
+sub word_stickers {
+  my( %f, %s, $k, $n, $l, $x );
+  $f{$_}++ for split //, shift;
+  my @q = [ 1, 0, my %t = %f ];
+  map { delete $t{$_} } split // for @_;
+  return 0 if keys %t;
+  while( ( $n, $l, %f ) = @{ shift @q } ) {
+    push @q, map {
+      $x = 0, %t = %f;
+      exists $t{$_} && ( $x=1, --$t{$_} || delete $t{$_} )
+        for split//, $_[$_];
+      !%t ? return $n : $x ? [ $n+1, $_, %t ] : ()
+    } $l..$#_;
+  }
+}
+
+is(      word_stickers(        @{$_->[0]} )    , $_->[1] ) for @TESTS2;
+done_testing();
+
+sub word_stickers_with_comments {
+  my( %f, %s, $k, $n, $l, $x );
+  $f{$_}++ for split //, shift; # count for letters
+  my %t = %f; # Check all letters on stickers
+  # Initialise queue - no stickers, initial freq.
+  my @q = [ 1, 0, my %t = %f ]; # Check can solve?
+  map { delete $t{$_} } split // for @_;
+  return 0 if keys %t; # if not return 0
+  my @q = [ 1, 0, %f ]; # [ $no+1, $last, %freqs ]
+  while( ($n,$l,%f) = @{ shift @q } ) {
+    push @q, map {
+      # Make copy of frequencies, set flag ($x)
+      # true once we use a letter on sticker,
+      # remove letters we have used up
+      $x = 0, %t = %f;
+      exists $t{$_} && ( $x=1, --$t{$_} || delete $t{$_} )
+        for split//, $_[$_];
+      # If none left return $n OR push entry onto
+      # queue, increasing count and setting new last
+      !%t ? return $n : $x ? [ $n+1, $_, %t ] : ()
+      # Loop from last used to remove duplicates
+    } $l..$#_;
+  }
+}
-- 
cgit