Merge pull request #1550 from southpawgeek/master

challenge 55 task 1

2 files changed, 47 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index 42398c3620..0d74b6c749 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
 .idea
 .precomp/
+.DS_Store
+.vstags
diff --git a/challenge-055/southpawgeek/perl/ch-1.pl b/challenge-055/southpawgeek/perl/ch-1.pl
new file mode 100644
index 0000000000..a4fb700785
--- /dev/null
+++ b/challenge-055/southpawgeek/perl/ch-1.pl
@@ -0,0 +1,45 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use feature qw/say/;
+
+my $B = "010";
+my @LR =(
+    {'L' => 0, 'R' => 0},
+    {'L' => 0, 'R' => 1},
+    {'L' => 0, 'R' => 2},
+    {'L' => 1, 'R' => 1},
+    {'L' => 1, 'R' => 2},
+    {'L' => 2, 'R' => 2});
+
+flip($B, $_) foreach @LR;
+
+my $pos;
+my @max1s;
+
+sub flip {
+    my ($B, $LR) = @_;
+    my @N = unpack '(A)*', $B;
+    my $L = $LR->{'L'};
+    my $R = $LR->{'R'};
+
+    say "L=$L, R=$R";
+
+    for ($L..$R) {
+        $N[$L] = 1 - $N[$L];
+        $L++;
+    }
+
+    say "$B -> ", @N;
+    say "-"x15;
+
+    my $x = ("@N" =~ tr/1/1/);
+    push @{$max1s[$x]}, $LR;
+    $pos = $x if $x > $pos;
+}
+
+say "max total positive bits: $pos";
+say "sets resulting in $pos positive bits";
+
+my $max = pop @max1s;
+say "L=", $_->{'L'}, " R=", $_->{'R'} foreach @$max;
\ No newline at end of file