From 0fe435254749250667c2f38566f12f617e270cab Mon Sep 17 00:00:00 2001
From: Myoungjin JEON <jeongoon@gmail.com>
Date: Mon, 28 Sep 2020 00:03:43 +1000
Subject: [ch-079/jeongoon] add ch-1.hs, just little bit more better ch-1.pl,
 ch-1.raku

---
 challenge-079/jeongoon/perl/ch-1.pl   | 35 ++++++++++++++++++++---------------
 challenge-079/jeongoon/raku/ch-1.raku |  2 +-
 2 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/challenge-079/jeongoon/perl/ch-1.pl b/challenge-079/jeongoon/perl/ch-1.pl
index 26043eefe3..9790cf08a2 100644
--- a/challenge-079/jeongoon/perl/ch-1.pl
+++ b/challenge-079/jeongoon/perl/ch-1.pl
@@ -16,23 +16,28 @@ BEGIN {
     $@ and usage(), exit 0;
 }
 
-#sub sumSection ($) {  # sum of the counts of bits between 2^(m) .. 2^(m+1)-1
-#    state @K = (1, 3);
-#    my $m = shift;
-#
-#    exists $K[$m] ? $K[$m] : ( $K[$m] = sum( 1<<$m, @K[0..$m-1] ) );
-#}
-
-#sub sumUptoPow2 ($) { # sum of bits between 0 .. 2^pow
-#    sum 1, # sumSection doesn't count the last bits of 2^pow
-#      map { sumSection $_ } 0 .. $_[0]-1
-#}
-
-# there is a simpler way to calculate, I realised today.
-# but this is not significantly faster than before.
+package older;
+use List::Util qw(sum);
+
+sub sumSection ($) {  # sum of the counts of bits between 2^(m) .. 2^(m+1)-1
+    state @K = (1, 3);
+    my $m = shift;
+
+    exists $K[$m] ? $K[$m] : ( $K[$m] = sum( 1<<$m, @K[0..$m-1] ) );
+}
+
+sub sumUptoPow2 ($) { # sum of bits between 0 .. 2^pow
+    sum 1, # sumSection doesn't count the last bits of 2^pow
+      map { sumSection $_ } 0 .. $_[0]-1
+}
+
+package main;
+
+# there is a simpler way to calculate, which I realised today.
+# but this method is not significantly faster than previous one.
 sub sumUptoPow2 ($) {
     my $pow = shift;
-    0.5 * $pow * (1 << $pow) + 1;
+    ( $pow * (1 << $pow) >> 1 ) + 1;  # eqv. ($pow * (2**$pow) / 2 ) + 1;
 }
 
 sub countSetBits ($);
diff --git a/challenge-079/jeongoon/raku/ch-1.raku b/challenge-079/jeongoon/raku/ch-1.raku
index 9957f92016..196bfb2cc4 100644
--- a/challenge-079/jeongoon/raku/ch-1.raku
+++ b/challenge-079/jeongoon/raku/ch-1.raku
@@ -20,7 +20,7 @@ our &naive = {[+] (.base(2).indices(1).elems for ^$_[0]+1)};
 #    [+] 1, |(sum-a-section($_) for 0..($pow-1));
 #}
 sub sum-upto-power2 ($pow) { # bits sum between 0 .. 2^pow
-    1 + 0.5 * $pow * (1+<$pow);
+    1 + ( $pow * (1+<$pow) ) +> 1
 }
 
 sub count-set-bits ( UInt \N ) {
-- 
cgit