Merge pull request #2808 from simongreen-net/swg-087

sgreen solution to challenge 087

4 files changed, 128 insertions, 2 deletions

diff --git a/challenge-087/sgreen/README.md b/challenge-087/sgreen/README.md
index c76bb4f87a..0281dfc367 100644
--- a/challenge-087/sgreen/README.md
+++ b/challenge-087/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 086
+# The Weekly Challenge 087
 
-Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-086-1k2h)
+Solution by Simon Green. [Blog](https://dev.to/simongreennet/weekly-challenge-087-6mjh)
diff --git a/challenge-087/sgreen/blog.txt b/challenge-087/sgreen/blog.txt
new file mode 100644
index 0000000000..44e25bbd7d
--- /dev/null
+++ b/challenge-087/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/weekly-challenge-087-6mj
diff --git a/challenge-087/sgreen/perl/ch-1.pl b/challenge-087/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..1ad925190c
--- /dev/null
+++ b/challenge-087/sgreen/perl/ch-1.pl
@@ -0,0 +1,41 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+use feature 'say';
+
+sub main {
+    my @N       = @_;
+    my @largest = ();
+    my @current = ();
+
+    # Check that we have integers
+    die "You must specify one or more integers\n" unless scalar(@N);
+    foreach (@N) {
+        die "The value '$_' does not appear to be an integer\n"
+          unless /^-?\d+$/;
+    }
+
+    # Go through the sorted list of numbers
+    foreach my $n ( sort { $a <=> $b } @N ) {
+        if ( scalar(@current) and $current[-1] != $n - 1 ) {
+            # Reset the array if the last number is not $n - 1
+            @current = ();
+        }
+
+        push @current, $n;
+        if ( scalar(@current) > scalar(@largest) ) {
+            @largest = @current;
+        }
+    }
+
+    if ( scalar(@largest) > 1 ) {
+        say 'Output: (', join( ', ', @largest ), ')';
+    }
+    else {
+        say 'Output: 0';
+    }
+}
+
+main(@ARGV);
diff --git a/challenge-087/sgreen/perl/ch-2.pl b/challenge-087/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..c65c94d299
--- /dev/null
+++ b/challenge-087/sgreen/perl/ch-2.pl
@@ -0,0 +1,84 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+use List::Util qw(min);
+
+sub _count_ones {
+    # Count the number of sequencial ones in the row. There might be a
+    #  better way, but at least this works™
+    my $count = 0;
+    ++$count while $_[$count];
+    return $count;
+}
+
+sub main {
+    my @array = ();
+
+    # Process the input
+    foreach my $row (@_) {
+        $row =~ s/[^01]//g;
+        die "Each row must have at least two '0' or '1'\n" if length($row) < 2;
+        push @array, [ split //, $row ];
+    }
+
+    # Sanity check
+    die "You must specify at least two rows\n" if scalar(@array) < 2;
+    foreach my $row ( 1 .. $#array ) {
+        die "Each row must have the same number of colums\n"
+          if scalar( @{ $array[0] } ) != scalar( @{ $array[$row] } );
+    }
+
+    my $rows = scalar(@array);
+    my $cols = scalar( @{ $array[0] } );
+
+    my $max_width  = 0;
+    my $max_height = 0;
+
+    # Go through each rows and column
+    # The top left of a square cannot be on the right or bottom row (hence -2)
+    my @squares = ();
+    foreach my $row ( 0 .. $rows - 2 ) {
+        foreach my $col ( 0 .. $cols - 2 ) {
+            my $this_width =
+              _count_ones( @{ $array[$row] }[ $col .. $cols - 1 ] );
+
+            # No rectangle if this row has < 2 zeros
+            next if $this_width < 2;
+
+            # Find the maximum rectangle size
+            for my $this_height ( 2 .. $rows - $row ) {
+                $this_width = min(
+                    $this_width,
+                    _count_ones(
+                        @{ $array[ $row + $this_height - 1 ] }
+                          [ $col .. $cols - 1 ]
+                    )
+                );
+
+                # No more rectangles can be made from this starting point
+                last if $this_width < 2;
+
+                # Update the largest rectangle if this one is bigger
+                if ( $this_width * $this_height > $max_width * $max_height ) {
+                    $max_width  = $this_width;
+                    $max_height = $this_height;
+                }
+            }
+        }
+    }
+
+    # Display the output
+    if ($max_width) {
+        for ( 1 .. $max_height ) {
+            say '[ ', ( '1 ' x $max_width ), ']';
+        }
+    }
+    else {
+        say 'Output: 0';
+    }
+}
+
+main(@ARGV);