Challenge 079 by sgreen

5 files changed, 133 insertions, 33 deletions

diff --git a/challenge-079/sgreen/README.md b/challenge-079/sgreen/README.md
index f4852a4fd6..356818eca9 100644
--- a/challenge-079/sgreen/README.md
+++ b/challenge-079/sgreen/README.md
@@ -1,34 +1,3 @@
-# The Weekly Challenge 078
+# The Weekly Challenge 079
 
-Solution by Simon Green.
-
-## TASK #1 › Leader Element
-
-Both of these week's tasks seemed pretty straight forward, so there's not much commentary from me this week. For the first task, I worked through the array (left to right) and displayed the number if the value is greater than all the values to the right.
-
-I manually added the last number as by definition (there are no values to the right), it will be greater (even if it is a negative integer).
-
-An alternate solution would be to work right to left keeping count of the maximum seen value so far and display values that exceeded that value. Definitely more efficient, but a little more complex.
-
-### Examples
-
-    » ./ch-1.pl 9 10 7 5 6 1
-    (10, 7, 6, 1)
-
-    » ./ch-1.pl 3 4 5
-    (5)
-
-## TASK 2 › Left Rotation
-
-For this task, I read in the two arrays and checked all the values in the second array were less than the number of items in the first array. I worked through the second array to display the rotated list using `@array[ $offset .. $#array, 0 .. $offset - 1 ]` to show the values in the correct order. The exception is when the offset was 0. In this case, I displayed the original array unaltered.
-
-### Examples
-
-    » ./ch-2.pl "(10 20 30 40 50)" "(3 4)"
-    [40 50 10 20 30]
-    [50 10 20 30 40]
-
-    » ./ch-2.pl "(7 4 2 6 3)" "(1 3 4)"
-    [4 2 6 3 7]
-    [6 3 7 4 2]
-    [3 7 4 2 6]
\ No newline at end of file
+Solution by Simon Green. [Blog](https://dev.to/simongreennet/the-weekly-challenge-079-1jel)
diff --git a/challenge-079/sgreen/blog.txt b/challenge-079/sgreen/blog.txt
new file mode 100644
index 0000000000..3ca8d73c0a
--- /dev/null
+++ b/challenge-079/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/the-weekly-challenge-079-1jel
diff --git a/challenge-079/sgreen/perl/ch1a.pl b/challenge-079/sgreen/perl/ch1a.pl
new file mode 100755
index 0000000000..a3f6b6e817
--- /dev/null
+++ b/challenge-079/sgreen/perl/ch1a.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+sub main {
+    my $N     = shift;
+    my $count = 0;
+
+    # Sanity check
+    die "Please enter a positive integer\n" unless $N;
+    die "The value '$N' is not a positive integer\n"
+      unless $N =~ /^[1-9][0-9]*$/;
+
+    foreach my $i ( 1 .. $N ) {
+        my $str = sprintf '%b', $i;
+        $count += $str =~ tr/1//;
+    }
+
+    printf qq(%d %% %d = %d\n), $count, 1000000007, $count % 1000000007;
+}
+
+main(@ARGV);
diff --git a/challenge-079/sgreen/perl/ch1b.pl b/challenge-079/sgreen/perl/ch1b.pl
new file mode 100755
index 0000000000..ed0628ca60
--- /dev/null
+++ b/challenge-079/sgreen/perl/ch1b.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+
+sub main {
+    my $N     = shift;
+    my $count = 0;
+
+    # Sanity check
+    die "Please enter a positive integer\n" unless $N;
+    die "The value '$N' is not a positive integer\n"
+      unless $N =~ /^[1-9][0-9]*$/;
+
+    my $b = 1;
+    while ( $b < $N ) {
+        foreach my $i ( 1 .. $N ) {
+            $count++ if $i & $b;
+        }
+        $b *= 2;
+    }
+
+    printf qq(%d %% %d = %d\n), $count, 1000000007, $count % 1000000007;
+}
+
+main(@ARGV);
+
diff --git a/challenge-079/sgreen/perl/ch2.pl b/challenge-079/sgreen/perl/ch2.pl
new file mode 100755
index 0000000000..670db22c6b
--- /dev/null
+++ b/challenge-079/sgreen/perl/ch2.pl
@@ -0,0 +1,78 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use List::Util qw(min max);
+use 5.10.1;
+
+sub _display_histogram {
+    my ( $array, $fills ) = @_;
+
+    my $max_value = max @$array;
+
+    # Build an array of arrays with the height of the block, and the
+    # height of the fill line
+    my @columns =
+      map { [ $array->[$_], $array->[$_] + $fills->[$_] ] } ( 0 .. $#$array );
+
+    my $width = length($max_value);
+    my $empty = ' ' x ($width);
+    my $fill  = '·' . ( ' ' x ( $width - 1 ) );
+    my $block = '#' . ( ' ' x ( $width - 1 ) );
+
+    for ( my $i = $max_value ; $i > 0 ; $i-- ) {
+        say join ' ', sprintf( "\%${width}d", $i ),
+          map { $_->[0] >= $i ? $block : $_->[1] >= $i ? $fill : $empty }
+          @columns;
+    }
+
+    # The dashes row
+    say join ' ', ( '-' x $width ) x ( $#$array + 2 );
+
+    # And finally the counts for each array
+    say join ' ', ( ' ' x $width ), map { sprintf "\%-${width}s", $_ } @$array;
+}
+
+sub main {
+    my @array = @_;
+
+    # Sanity check
+    die "You must enter at least one value" if $#array == -1;
+
+    foreach my $value (@array) {
+        die "Value '$value' is not an integer\n"
+          unless $value =~ /^[1-9][0-9]*$/;
+    }
+
+    # This stores the results
+    my @fills = (0);    # The first column cannot hold water
+    my $drops = 0;
+
+    # Let's calculate the storage capcity for each column
+    # (except first and last)
+    foreach my $col ( 1 .. $#array - 1 ) {
+        my $height = $array[$col];
+
+        # The maximum height to the left and to the right
+        my $left  = max map { $array[$_] } ( 0 .. $col - 1 );
+        my $right = max map { $array[$_] } ( $col + 1 .. $#array );
+
+        # We can fill to the minimum of left and right, minus the
+        # height of this column
+        my $x = min( $left, $right ) - $height;
+        $x = 0 if $x < 0;
+
+        $drops += $x;
+        push @fills, $x;
+    }
+
+    # The last column cannot hold water
+    push @fills, 0;
+
+    # Display the history
+    _display_histogram( \@array, \@fills );
+
+    say "\nResult is $drops";
+}
+
+main(@ARGV);