From 3368166499ec496ca0a6c8564d0c33f65d4adc07 Mon Sep 17 00:00:00 2001
From: Jörg Sommrey <28217714+jo-37@users.noreply.github.com>
Date: Sat, 20 Mar 2021 11:24:58 +0100
Subject: avoid elements outside pascal's triangle

---
 challenge-104/jo-37/perl/ch-1.pl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

(limited to 'challenge-104')

diff --git a/challenge-104/jo-37/perl/ch-1.pl b/challenge-104/jo-37/perl/ch-1.pl
index 83e366daa3..c06ed04f32 100755
--- a/challenge-104/jo-37/perl/ch-1.pl
+++ b/challenge-104/jo-37/perl/ch-1.pl
@@ -3,6 +3,7 @@
 use v5.16;
 use Test2::V0;
 use Math::Prime::Util 'binomial';
+use Math::Utils 'ceil';
 use List::Util 'reduce';
 use experimental 'signatures';
 
@@ -34,7 +35,7 @@ EOS
 
 ### Input and Output
 
-my $n = shift || 50;
+my $n = shift // 50;
 if ($fusc) {
     say "fusc($n)=" x !!$verbose, fusc($n);
 } else {
@@ -47,9 +48,11 @@ if ($fusc) {
 # Non-recursive implementation of fusc according to
 # http://oeis.org/A002487
 sub fusc ($n) {
-    reduce {$a += $b % 2} 0, map binomial($_, $n - $_ - 1), 0 .. $n - 1;
+    reduce {$a += $b % 2} 0, map binomial($_, $n - $_ - 1),
+        ceil(($n - 1) / 2) .. $n - 1;
 }
 
+
 ### Tests
 
 sub run_tests {
-- 
cgit