From fe23e322916422d3390f559c41544aff4ee18ddb Mon Sep 17 00:00:00 2001
From: James Smith <js5@sanger.ac.uk>
Date: Sun, 29 Jan 2023 19:08:58 +0000
Subject: Update ch-2.pl

---
 challenge-201/james-smith/perl/ch-2.pl | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/challenge-201/james-smith/perl/ch-2.pl b/challenge-201/james-smith/perl/ch-2.pl
index fd7f700762..64a80fcb84 100644
--- a/challenge-201/james-smith/perl/ch-2.pl
+++ b/challenge-201/james-smith/perl/ch-2.pl
@@ -5,34 +5,44 @@ use warnings;
 use feature qw(say);
 use Test::More;
 use Benchmark qw(cmpthese timethis);
+use List::Util qw(sum0);
 
 my @TESTS = ([5,7],[10,42],[15,176],[20,627],[25,1958],[30,5604],[35,14883],[40,37338],[45,89134],[50,204226]);
 my %cache;
 
-is( piles(   $_->[0]), $_->[1] ) for @TESTS;
-is( piles_2( $_->[0]), $_->[1] ) for @TESTS;
-is( piles_q( $_->[0]), $_->[1] ) for @TESTS;
+(%cache=()), is( piles(   $_->[0]), $_->[1] ) for @TESTS;
+(%cache=()), is( piles_0( $_->[0]), $_->[1] ) for @TESTS;
+(%cache=()), is( piles_2( $_->[0]), $_->[1] ) for @TESTS;
+(%cache=()), is( piles_q( $_->[0]), $_->[1] ) for @TESTS;
 done_testing();
 
-cmpthese( -3, {
-  'piles'   => sub { %cache=();  piles(  $_->[0] ) for @TESTS },
+cmpthese( -2, {
+  'piles'   => sub { %cache=();   piles( $_->[0] ) for @TESTS },
+  'piles_0' => sub { %cache=(); piles_0( $_->[0] ) for @TESTS },
   'piles_2' => sub { %cache=(); piles_2( $_->[0] ) for @TESTS },
-  'piles_q' => sub {            piles_q( $_->[0] ) for @TESTS },
+  'piles_q' => sub { %cache=(); piles_q( $_->[0] ) for @TESTS },
 });
 
 sub piles {
   my($count,$n,$m)=(0,@_);
+  return 1 unless $n;
   $m//=$n;
   return $cache{"$n,$m"} if exists $cache{"$n,$m"};
-  return $cache{"$n,$m"} = 1 unless $n;
   $count += piles($n-$_,$_) for 1 .. ($m>$n?$n:$m);
   $cache{"$n,$m"}||=$count;
 }
 
+sub piles_0 {
+  return 1 unless $_[0];
+  $_[1]//=$_[0];
+  $cache{"@_"}//= sum0 map { piles_0( $_[0]-$_,$_ ) } 1 .. ($_[0]>$_[1]?$_[1]:$_[0]);
+}
+
 sub piles_2 {
   my($count,$n,$m)=(0,@_);
+  return 1 unless $n;
   $m//=$n;
-  $cache{"$n,$m"}//= $n ? sum_piles_2( $n, $m ) : 1;
+  $cache{"$n,$m"}//= sum_piles_2( $n, $m );
 }
 
 sub sum_piles_2 {
-- 
cgit