- Added Perl solution to Flip Binary.

2 files changed, 80 insertions, 0 deletions

diff --git a/challenge-055/mohammad-anwar/perl/ch-1.pl b/challenge-055/mohammad-anwar/perl/ch-1.pl
new file mode 100644
index 0000000000..bce2c5008c
--- /dev/null
+++ b/challenge-055/mohammad-anwar/perl/ch-1.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+my $binary_str = $ARGV[0];
+
+print "$binary_str => ", flip_binary($binary_str), "\n";
+
+#
+#
+# METHOD
+
+sub flip_binary {
+    my ($binary_str) = @_;
+
+    die "ERROR: Missing binary string.\n"
+        unless defined $binary_str;
+    die "ERROR: Invalid binary string [$binary_str].\n"
+        unless ($binary_str =~ /^[01]+$/);
+
+    my $result = {};
+    my $size = length($binary_str);
+    foreach my $left (1 .. $size) {
+        foreach my $right ($left .. $size) {
+            my $_binary_str = $binary_str;
+            foreach my $i ($left .. $right) {
+                --$i;
+                my $c = substr($_binary_str, $i, 1);
+                $c = ($c) ? (0) : (1);
+                substr($_binary_str, $i, 1, $c);
+            }
+            $result->{ sprintf("%s (%s,%s)", $_binary_str, $left, $right) } = ($_binary_str =~ tr/1/1/);
+        }
+    }
+
+    return [ sort { $result->{$b} <=> $result->{$a} } keys %$result ]->[0];
+}
diff --git a/challenge-055/mohammad-anwar/perl/ch-1a.pl b/challenge-055/mohammad-anwar/perl/ch-1a.pl
new file mode 100644
index 0000000000..55cf2a0c51
--- /dev/null
+++ b/challenge-055/mohammad-anwar/perl/ch-1a.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More;
+
+is (flip_binary("10001"), "11111 (2,4)");
+is (flip_binary("10101"), "11011 (2,4)");
+is (flip_binary("00101"), "11011 (1,4)");
+
+done_testing;
+
+#
+#
+# METHOD
+
+sub flip_binary {
+    my ($binary_str) = @_;
+
+    die "ERROR: Missing binary string.\n"
+        unless defined $binary_str;
+    die "ERROR: Invalid binary string [$binary_str].\n"
+        unless ($binary_str =~ /^[01]+$/);
+
+    my $result = {};
+    my $size = length($binary_str);
+    foreach my $left (1 .. $size) {
+        foreach my $right ($left .. $size) {
+            my $_binary_str = $binary_str;
+            foreach my $i ($left .. $right) {
+                --$i;
+                my $c = substr($_binary_str, $i, 1);
+                $c = ($c) ? (0) : (1);
+                substr($_binary_str, $i, 1, $c);
+            }
+            $result->{ sprintf("%s (%s,%s)", $_binary_str, $left, $right) } = ($_binary_str =~ tr/1/1/);
+        }
+    }
+
+    return [ sort { $result->{$b} <=> $result->{$a} } keys %$result ]->[0];
+}