Simon's solution to challenge 219

6 files changed, 110 insertions, 2 deletions

diff --git a/challenge-219/sgreen/README.md b/challenge-219/sgreen/README.md
index 393dc9b36a..b0c3afab92 100644
--- a/challenge-219/sgreen/README.md
+++ b/challenge-219/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 218
+# The Weekly Challenge 219
 
-Blog: [The one about maximums](https://dev.to/simongreennet/the-one-about-maximums-40cm)
+Blog: [The cheapest way to the square](https://dev.to/simongreennet/the-cheapest-way-to-the-square-1mhb)
diff --git a/challenge-219/sgreen/blog.txt b/challenge-219/sgreen/blog.txt
new file mode 100644
index 0000000000..a586d603aa
--- /dev/null
+++ b/challenge-219/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/the-cheapest-way-to-the-square-1mhb
\ No newline at end of file
diff --git a/challenge-219/sgreen/perl/ch-1.pl b/challenge-219/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..b6d438a88f
--- /dev/null
+++ b/challenge-219/sgreen/perl/ch-1.pl
@@ -0,0 +1,13 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub main (@array) {
+    @array = sort { $a <=> $b } map { $_**2 } @array;
+    say join ', ', @array;
+}
+
+main(@ARGV);
diff --git a/challenge-219/sgreen/perl/ch-2.pl b/challenge-219/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..cd81a701b6
--- /dev/null
+++ b/challenge-219/sgreen/perl/ch-2.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub buy_pass ( $passes, $travel_on ) {
+    if ( scalar(@$travel_on) == 0 ) {
+        return 0;
+    }
+
+    my $first_day     = $travel_on->[0];
+    my $minimum_spend = undef;
+
+    foreach my $days ( keys %$passes ) {
+        my $cost = $passes->{$days};
+        my $spend =
+          $cost +
+          buy_pass( $passes,
+            [ grep { $_ >= $first_day + $days } @$travel_on ] );
+        if ( not defined($minimum_spend) or $spend < $minimum_spend ) {
+            $minimum_spend = $spend;
+        }
+    }
+
+    return $minimum_spend;
+}
+
+sub main (@array) {
+    # Take the first three values off
+    my %passes = ();
+    $passes{1}  = shift @array;
+    $passes{7}  = shift @array;
+    $passes{30} = shift @array;
+
+    # Note the days we want to travel on
+    my @travel_on = sort { $a <=> $b } @array;
+    my $spent     = buy_pass( \%passes, \@travel_on );
+    say $spent;
+}
+
+main(@ARGV);
+
diff --git a/challenge-219/sgreen/python/ch-1.py b/challenge-219/sgreen/python/ch-1.py
new file mode 100755
index 0000000000..f3e6fb57f9
--- /dev/null
+++ b/challenge-219/sgreen/python/ch-1.py
@@ -0,0 +1,13 @@
+#!/usr/bin/env python
+
+import sys
+
+
+def main(array):
+    solution = sorted([x ** 2 for x in array])
+    print(*solution, sep=', ')
+
+
+if __name__ == '__main__':
+    array = [int(n) for n in sys.argv[1:]]
+    main(array)
diff --git a/challenge-219/sgreen/python/ch-2.py b/challenge-219/sgreen/python/ch-2.py
new file mode 100755
index 0000000000..a421ef00d9
--- /dev/null
+++ b/challenge-219/sgreen/python/ch-2.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+import sys
+
+
+def buy_pass(passes, travel_on):
+    if len(travel_on) == 0:
+        return 0
+
+    first_day = travel_on[0]
+    minimum_spend = None
+
+    for days, cost in passes.items():
+        spend = cost + \
+            buy_pass(passes, [i for i in travel_on if i >= first_day + days])
+        if minimum_spend is None or spend < minimum_spend:
+            minimum_spend = spend
+
+    return minimum_spend
+
+
+def main(array):
+    # Take the first three values off
+    passes = {}
+    passes[1] = array.pop(0)
+    passes[7] = array.pop(0)
+    passes[30] = array.pop(0)
+
+    # Note the days we want to travel on
+    travel_on = sorted(array)
+    spent = buy_pass(passes, travel_on)
+    print(spent)
+
+
+if __name__ == '__main__':
+    array = [int(n) for n in sys.argv[1:]]
+    main(array)