perl solution for task 1

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diff --git a/challenge-333/jkstill/README b/challenge-333/jkstill/README
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+
+Solution by Jared Still
+
diff --git a/challenge-333/jkstill/perl/ch-1.pl b/challenge-333/jkstill/perl/ch-1.pl
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+#!/usr/bin/env perl
+
+# jared still - jkstill@gmail.com
+
+=head1 Perl Weekly Challenge 333
+
+ Task 1: Straight Line
+
+ Determine if a set of points are collinear.
+
+ There is a well known algorithm that uses the cross product of three points to determine if they are collinear.
+
+ So, I use that, and then extended it to work with an abitrary number of points.
+
+ Flip the $useChallengeList from 1 to 0 to use the extended data.
+
+=cut
+
+use strict;
+use warnings;
+use Data::Dumper;
+$Data::Dumper::Indent = 0;
+$Data::Dumper::Terse = 1;
+
+my @expectedResults;
+my @list;
+
+my $useChallengeList = 0; # set to 1 to use the challenge list, 0 to use the custom list
+
+if ($useChallengeList) {
+
+@list = (
+	[[2, 1], [2, 3], [2, 5]], # collinear
+	[[1, 4], [3, 4], [10, 4]], # collinear
+	[[0, 0], [1, 1], [2, 3]], # not collinear
+	[[1, 1], [1, 1], [1, 1]], # collinear
+	[[1000000, 1000000], [2000000, 2000000], [3000000, 3000000]] # collinear
+);
+
+ @expectedResults = (
+	1, # collinear
+	1, # collinear
+	0, # not collinear
+	1, # collinear
+	1  # collinear
+);
+
+} else {
+
+	# head1 custom list
+
+	@list = (
+		[[1,1]],
+		[[0,0], [6,7]],
+		[[2, 1], [2, 3], [2, 5]],
+		[[0, 0], [1, 1], [2, 3], [3,4]],
+		[[1, 2], [3, 4], [5, 6]],
+		[[1, 1], [2, 2], [3, 3]],
+		[[0, 0], [0, 0], [0, 0]],
+		[[1, 2], [3, 4], [5, 6]],
+		[[1000000, 1000000], [2000000, 2000000], [3000000, 3000000]] ,
+
+		# Collinear
+		[[0,0], [1,1], [2,2], [3,3], [4,4], [5,5], [6,6], [7,7], [8,8]],
+
+		# Non-Collinear
+		[[0,0], [1,1], [2,2], [3,3], [4,4], [5,4], [6,6], [7,7], [8,8]],
+		
+		#Collinear 
+		[[0,0], [1,1], [2,2], [3,3], [4,4], [5,5], [6,6], [7,7], [8,8], [9,9]],
+
+		# Non-Collinear 
+		[[0,0], [1,1], [2,2], [3,3], [4,4], [5,5], [6,6], [7,7], [8,8], [9,9],[10,11]],
+		
+		# Non-Collinear
+		[[0,0], [1,1], [2,2], [3,3], [4,2], [5,1], [5,2], [6,3], [7,4]]
+	);
+
+	# 1: collinear
+	# 0: not collinear
+	@expectedResults = (
+		1,
+		1,
+		1,
+		0,
+		1,
+		1,
+		1,
+		1,
+		1,
+		1,
+		0,
+		1,
+		0,
+		0,
+	);
+
+}
+
+print '@list = ( ' . Dumper(\@list) . " )\n\n";
+
+# Calculate the cross product of three points at a time.
+# Advance through the list of points, checking three at a time.
+# If the number of points <= 2, they are collinear.
+
+my $e = 0;
+
+foreach my $chkListRef (@list) {
+
+	print "Checking points: " . Dumper($chkListRef) . "\n";
+
+	my $numberOfPoints = scalar(@$chkListRef);
+	my $remainder = $numberOfPoints % 3;
+	my $isCollinear = 1;
+
+	# walk the list of lists of points, advancing 1 point at a time
+	for ( my $i = 0; $i <= scalar(@$chkListRef) - 3; $i++ ) {
+
+		my $p1 = defined $chkListRef->[$i] ? $chkListRef->[$i] : undef;
+		my $p2 = defined $chkListRef->[$i + 1] ? $chkListRef->[$i + 1] : undef;
+		my $p3 = defined $chkListRef->[$i + 2] ? $chkListRef->[$i + 2] : undef;
+
+		$isCollinear = crossProduct( $p1, $p2, $p3 ) ? 1 : 0;
+		last unless $isCollinear;
+
+	}
+
+	print "expected:results $expectedResults[$e]:$isCollinear \n";
+	print "\n";
+
+	$e++;
+
+}
+
+# Check if the points are collinear.
+# check three points at a time
+# If the cross product is zero, the points are collinear.
+sub crossProduct {
+	my ( $p1, $p2, $p3 ) = @_;
+	# if less than 3 points, they are collinear
+	return 1 if ( !defined $p3 );
+	return ( ( $p2->[0] - $p1->[0] ) * ( $p3->[1] - $p1->[1] ) - ( $p2->[1] - $p1->[1] ) * ( $p3->[0] - $p1->[0] ) ) == 0;
+}
+
+