From edb52ce397db24e01e8e4ddd9a17a2e6a6192143 Mon Sep 17 00:00:00 2001
From: Niels van Dijke <perlboy@cpan.org>
Date: Tue, 27 Jul 2021 23:22:14 +0000
Subject: Task 2 - Check diffently distance frequency count * Add equilateral
 triangle - Thanks to James Curtis-Smith

---
 challenge-123/perlboy1967/perl/ch-2.pl | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/challenge-123/perlboy1967/perl/ch-2.pl b/challenge-123/perlboy1967/perl/ch-2.pl
index cabec1e3e8..15a7207ac2 100755
--- a/challenge-123/perlboy1967/perl/ch-2.pl
+++ b/challenge-123/perlboy1967/perl/ch-2.pl
@@ -11,8 +11,6 @@ use v5.16;
 use strict;
 use warnings;
 
-use List::MoreUtils qw(frequency);
-
 use Test::More;
 
 # Prototype(s)
@@ -27,6 +25,7 @@ my $tests = [
    [ [ 0, 1],[ 1, 2],[ 2, 1],[ 1, 0], 1 ],
    [ [-5, 0],[ 5, 0],[ 0, 1],[ 0,-1], 0 ],
    [ [-1, 0],[ 5, 0],[ 0, 1],[ 0,-1], 0 ],
+   [ [-1, 0],[ 1, 0],[ 0, sqrt(3)],[ 0, sqrt(3)/3], 0 ], # equilateral triangle
 ];
 
 foreach my $t (@$tests) {
@@ -40,7 +39,7 @@ done_testing();
 sub areSquarePoints(\@) {
   my ($ar) = @_;
 
-  my @dP;
+  my %dP;
 
   # If all points given are coordinates of a square
   # then the distance between one point and the other three
@@ -49,18 +48,14 @@ sub areSquarePoints(\@) {
     my @d;
     foreach my $j (0 .. 3) {
       next if ($i == $j);
-      push(@d,sqrt(($ar->[$i][0]-$ar->[$j][0])**2 +
-                   ($ar->[$i][1]-$ar->[$j][1])**2));
+      $dP{sqrt(($ar->[$i][0]-$ar->[$j][0])**2 +
+               ($ar->[$i][1]-$ar->[$j][1])**2)}++;
     }
-    my %f = frequency @d;
-    push(@dP,keys %f);
   }
 
-  # If all four points give same distance 'frequencies'
-  # then we have a square
-  my %f = frequency @dP;
+  my @v = sort { $b <=> $a } values %dP;
 
-  return 1 if (scalar keys %f == 2);
+  return 1 if ($v[0] == 8 && $v[1] == 4);
 
   return 0;
 }
-- 
cgit 


From 337606a8afa9a655a3c1a4dc404714d3de6339ba Mon Sep 17 00:00:00 2001
From: Niels van Dijke <perlboy@cpan.org>
Date: Tue, 27 Jul 2021 23:35:21 +0000
Subject: Cleanup and slightly shorter version

---
 challenge-123/perlboy1967/perl/ch-2.pl | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/challenge-123/perlboy1967/perl/ch-2.pl b/challenge-123/perlboy1967/perl/ch-2.pl
index 15a7207ac2..926188c449 100755
--- a/challenge-123/perlboy1967/perl/ch-2.pl
+++ b/challenge-123/perlboy1967/perl/ch-2.pl
@@ -45,7 +45,6 @@ sub areSquarePoints(\@) {
   # then the distance between one point and the other three
   # will give 2 identical and on other
   foreach my $i (0 .. 3) {
-    my @d;
     foreach my $j (0 .. 3) {
       next if ($i == $j);
       $dP{sqrt(($ar->[$i][0]-$ar->[$j][0])**2 +
@@ -55,8 +54,6 @@ sub areSquarePoints(\@) {
 
   my @v = sort { $b <=> $a } values %dP;
 
-  return 1 if ($v[0] == 8 && $v[1] == 4);
-
-  return 0;
+  return ($v[0] == 8 && $v[1] == 4 ? 1 : 0);
 }
 
-- 
cgit