From 3eac84cedbe50a028765be18bf09465ad1edc539 Mon Sep 17 00:00:00 2001
From: Niels van Dijke <perlboy@cpan.org>
Date: Mon, 22 May 2023 21:17:18 +0000
Subject: w218 - Task 1 & 2

---
 challenge-218/perlboy1967/perl/ch1.pl | 48 +++++++++++++++++++++++++++++
 challenge-218/perlboy1967/perl/ch2.pl | 57 +++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100755 challenge-218/perlboy1967/perl/ch1.pl
 create mode 100755 challenge-218/perlboy1967/perl/ch2.pl

diff --git a/challenge-218/perlboy1967/perl/ch1.pl b/challenge-218/perlboy1967/perl/ch1.pl
new file mode 100755
index 0000000000..79ef7e0701
--- /dev/null
+++ b/challenge-218/perlboy1967/perl/ch1.pl
@@ -0,0 +1,48 @@
+#!/bin/perl
+
+=pod
+
+The Weekly Challenge - 217
+- https://theweeklychallenge.org/blog/perl-weekly-challenge-217
+
+Author: Niels 'PerlBoy' van Dijke
+
+Task 1: Maximum Product
+Submitted by: Mohammad S Anwar
+
+You are given a list of 3 or more integers.
+
+Write a script to find the 3 integers whose product is the maximum and return it.
+
+=cut
+
+use v5.16;
+
+use common::sense;
+
+use List::Util qw(product);
+
+use Test::More;
+
+sub maxProduct (@) {
+  my (@n,@p);
+
+  for (@_) {
+    $_ < 0 ? push(@n,$_) : 
+    $_ > 0 ? push(@p,$_) :
+    0;
+  }
+
+  @n = sort {$a <=> $b} @n;
+  pop @n if (@n % 2);
+
+  product(@p,@n);
+}
+
+is(maxProduct(3,2,1),6);
+is(maxProduct(4,1,3,2),24);
+is(maxProduct(-1,0,1,3,1),3);
+is(maxProduct(-8,2,-9,0,-4,3),432);
+is(maxProduct(-3,-2,-1,0,1,2,3),36);
+
+done_testing;
diff --git a/challenge-218/perlboy1967/perl/ch2.pl b/challenge-218/perlboy1967/perl/ch2.pl
new file mode 100755
index 0000000000..9eaefc1b60
--- /dev/null
+++ b/challenge-218/perlboy1967/perl/ch2.pl
@@ -0,0 +1,57 @@
+#!/bin/perl
+
+=pod
+
+The Weekly Challenge - 217
+- https://theweeklychallenge.org/blog/perl-weekly-challenge-217
+
+Author: Niels 'PerlBoy' van Dijke
+
+Task 2: Matrix Score
+Submitted by: Mohammad S Anwar
+
+You are given a m x n binary matrix i.e. having only 1 and 0.
+
+You are allowed to make as many moves as you want to get the highest score.
+
+|| A move can be either toggling each value in a row or column.
+
+To get the score, convert the each row binary to dec and return the sum.
+
+=cut
+
+use v5.16;
+
+use common::sense;
+
+use List::Util qw(sum);
+
+use Test::More;
+
+sub matrixScore (\@) {
+  my ($ar) = @_;
+  my $nR = @$ar - 1;
+  my $nC = @{$ar->[0]} - 1;
+
+  # First make sure each row has its MSB set
+  for (@$ar) {
+    map { $_ = ++$_ % 2 } @$_ if ($$_[0] == 0);
+  }
+
+  for my $c (1 .. $nC) {
+    my $ones = grep { $ar->[$_][$c] == 1 } (0 .. $nR);
+    # Flip bits in column C if number of '1's ir smaller than rows
+    map { $ar->[$_][$c] = ++$$ar[$_][$c] % 2 } (0 .. $nR) 
+      if ($ones < $nR);
+  }
+
+  return sum(map{oct('0b'.join('',@$_))} @$ar);
+}
+
+
+is(matrixScore(@{[[0,0,1,1],
+                  [1,0,1,0],
+                  [1,1,0,0],
+                 ]}),39);
+
+done_testing;
-- 
cgit 


From b9798d4f8d8d14c5230c442253ad52e6994da391 Mon Sep 17 00:00:00 2001
From: Niels van Dijke <perlboy@cpan.org>
Date: Mon, 22 May 2023 21:42:43 +0000
Subject: Some comments

---
 challenge-218/perlboy1967/perl/ch1.pl | 3 +++
 challenge-218/perlboy1967/perl/ch2.pl | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/challenge-218/perlboy1967/perl/ch1.pl b/challenge-218/perlboy1967/perl/ch1.pl
index 79ef7e0701..48bbc2aa76 100755
--- a/challenge-218/perlboy1967/perl/ch1.pl
+++ b/challenge-218/perlboy1967/perl/ch1.pl
@@ -27,12 +27,15 @@ use Test::More;
 sub maxProduct (@) {
   my (@n,@p);
 
+  # Find negative and positive factors
   for (@_) {
     $_ < 0 ? push(@n,$_) : 
     $_ > 0 ? push(@p,$_) :
     0;
   }
 
+  # If we have an odd number of negative factors, 
+  # ditch the one closest to zero
   @n = sort {$a <=> $b} @n;
   pop @n if (@n % 2);
 
diff --git a/challenge-218/perlboy1967/perl/ch2.pl b/challenge-218/perlboy1967/perl/ch2.pl
index 9eaefc1b60..757630f319 100755
--- a/challenge-218/perlboy1967/perl/ch2.pl
+++ b/challenge-218/perlboy1967/perl/ch2.pl
@@ -40,7 +40,8 @@ sub matrixScore (\@) {
 
   for my $c (1 .. $nC) {
     my $ones = grep { $ar->[$_][$c] == 1 } (0 .. $nR);
-    # Flip bits in column C if number of '1's ir smaller than rows
+
+    # Flip bits in column C if number of '1's is smaller than # of rows
     map { $ar->[$_][$c] = ++$$ar[$_][$c] % 2 } (0 .. $nR) 
       if ($ones < $nR);
   }
-- 
cgit