From fa16306034b25e220fdbd125f24dda30994bf9dc Mon Sep 17 00:00:00 2001
From: andrezgz <andrezgz@gmail.com>
Date: Tue, 24 Sep 2019 17:21:00 -0300
Subject: challenge-027 andrezgz solution

---
 challenge-027/andrezgz/perl5/ch-1.pl | 46 ++++++++++++++++++++++++++++++++++++
 challenge-027/andrezgz/perl5/ch-2.pl | 18 ++++++++++++++
 2 files changed, 64 insertions(+)
 create mode 100644 challenge-027/andrezgz/perl5/ch-1.pl
 create mode 100644 challenge-027/andrezgz/perl5/ch-2.pl

diff --git a/challenge-027/andrezgz/perl5/ch-1.pl b/challenge-027/andrezgz/perl5/ch-1.pl
new file mode 100644
index 0000000000..154fb49efc
--- /dev/null
+++ b/challenge-027/andrezgz/perl5/ch-1.pl
@@ -0,0 +1,46 @@
+#!/usr/bin/perl
+
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-027/
+# Task #1
+# Write a script to find the intersection of two straight lines.
+# The co-ordinates of the two lines should be provided as command line parameter. For example:
+# The two ends of Line 1 are represented as co-ordinates (a,b) and (c,d).
+# The two ends of Line 2 are represented as co-ordinates (p,q) and (r,s).
+# The script should print the co-ordinates of point of  intersection of the above two lines.
+
+use strict;
+use warnings;
+
+# From https://en.wikipedia.org/wiki/Line%E2%80%93line_intersection
+
+my $usage_messsage = <<EOT;
+Usage: $0 a,b c,d p,q r,s
+* Each pair represents the co-ordinates of a point.
+* (a,b) (c,d) define the first segment.
+* (p,q) (r,s) define the second segment.
+
+Example:
+$0 1,1 5,1 2,0 2,6
+Intersection point (2.00,1.00)
+
+EOT
+die $usage_messsage if @ARGV != 4;
+
+my ($x1,$y1) = split /,/, shift;
+my ($x2,$y2) = split /,/, shift;
+my ($x3,$y3) = split /,/, shift;
+my ($x4,$y4) = split /,/, shift;
+
+my $d = ($x1-$x2) * ($y3-$y4) - ($y1-$y2) * ($x3-$x4);
+die "Segments are parallels" unless $d;
+
+my $t = ( ($x1-$x3) * ($y3-$y4) - ($y1-$y3) * ($x3-$x4) ) / $d;
+die "Intersection point out of first segment" if ($t>1 || $t<0) ;
+
+my $u = -1 * ( ($x1-$x2) * ($y1-$y3) - ($y1-$y2) * ($x1-$x3) ) / $d;
+die "Intersection point out of second segment" if ($u>1 || $u<0) ;
+
+my $px = $x1 + $t * ($x2-$x1);
+my $py = $y1 + $t * ($y2-$y1);
+
+printf "Intersection point (%.2f,%.2f)",$px,$py;
diff --git a/challenge-027/andrezgz/perl5/ch-2.pl b/challenge-027/andrezgz/perl5/ch-2.pl
new file mode 100644
index 0000000000..9e1ed73652
--- /dev/null
+++ b/challenge-027/andrezgz/perl5/ch-2.pl
@@ -0,0 +1,18 @@
+#!/usr/bin/perl
+
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-027/
+# Task #2
+# Write a script that allows you to capture/display historical data.
+# It could be an object or a scalar. For example
+# my $x = 10; $x = 20; $x -= 5;
+# After the above operations, it should list $x historical value in order.
+
+use strict;
+use warnings;
+
+my $x;
+my $x_ops= 'my $x = 10; $x = 20; $x -= 5;';
+
+my @log;
+push @log, eval $_ for (split /;/, $x_ops);
+print join "\n",@log;
-- 
cgit