Added solution for challenge 2 for week 91.

1 files changed, 62 insertions, 0 deletions

diff --git a/challenge-091/jcrosswh/perl/ch-2.pl b/challenge-091/jcrosswh/perl/ch-2.pl
new file mode 100644
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+++ b/challenge-091/jcrosswh/perl/ch-2.pl
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+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+=head1 NAME
+
+PWC 091 Challenge 2
+
+=head1 SYNOPSIS
+
+  $ ch-2.pl 1,2,3
+  1
+
+  $ ch-2.pl 5,2,3
+  0
+
+=head1 DESCRIPTION
+
+Given an array of positive numbers @N, where the value at each index determines
+how far you are allowed to jump. This script will decide if you can jump,
+exactly, to the last index. It will print 1 if you are able to reach the last
+index or 0 if you can't.
+
+=head1 SOLUTION
+
+First this script will sanatize the input, making sure that only a list of
+numbers separated by commas was passed in.  The script will parse and store
+these numbers in an array.  Then we will "walk" the array by trying to jump
+exactly to the end, and if that's not possible, try to jump forward, and if we
+can't do that then inform the user that it's not possible.
+
+=head1 AUTHORS
+
+Joel Crosswhite E<lt>joel.crosswhite@ix.netcom.comE<gt>
+
+=cut
+
+my $input = $ARGV[0];
+if (!defined($input) || $input !~ m/^([1-9],)*[1-9]$/) {
+    print "Usage: ch-2.pl <positive integer>,<positive integer>,...\n";
+    exit 1;
+}
+
+my @N = split(/,/, $input);
+my $length = scalar(@N);
+my $index = 0;
+
+while (1) {
+    
+    my $current_number = $N[$index];
+    
+    if ($current_number == $length - $index) {
+        print 1 . "\n";
+        exit 0;
+    } elsif ($current_number < $length - $index) {
+        $index += $N[$index];
+    } else {
+        print 0 . "\n";
+        exit 0;
+    }
+}