Merge pull request #3492 from gnustavo/099

Add Gustavo Chaves's solutions to challenge 099

2 files changed, 70 insertions, 0 deletions

diff --git a/challenge-099/gustavo-chaves/perl/ch-1.pl b/challenge-099/gustavo-chaves/perl/ch-1.pl
new file mode 100755
index 0000000000..a11b6d7390
--- /dev/null
+++ b/challenge-099/gustavo-chaves/perl/ch-1.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/env perl
+
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-099/
+# TASK #1 › Pattern Match
+
+use 5.030;
+use warnings;
+
+my ($S, $P) = @ARGV;
+
+say "Pattern: '$P'";
+
+say match($P, $S) ? "Matches: " : "Does not match: ", "'$S'";
+
+sub match {
+    my ($pattern, $string) = @_;
+
+    my ($s, $p) = (0, 0);
+
+  CHAR:
+    while ($p < length($pattern) && $s < length($string)) {
+        my $c = substr($pattern, $p, 1);
+
+        if ($c eq '?') {
+            ++$s;
+            ++$p;
+        } elsif ($c eq '*') {
+            my $patterntail = substr($pattern, $p+1);
+            for (my $i=$s; $i < length($string); ++$i) {
+                return 1 if match($patterntail, substr($string, $i));
+            }
+            return 0;
+        } elsif ($c eq substr($string, $s, 1)) {
+            ++$s;
+            ++$p;
+        } else {
+            return 0;
+        }
+    }
+
+    return $p == length($pattern) && $s == length($string);
+}
diff --git a/challenge-099/gustavo-chaves/perl/ch-2.pl b/challenge-099/gustavo-chaves/perl/ch-2.pl
new file mode 100755
index 0000000000..25f36ff228
--- /dev/null
+++ b/challenge-099/gustavo-chaves/perl/ch-2.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-099/
+# TASK #2 › Unique Subsequence
+
+use 5.030;
+use warnings;
+
+my ($S, $T) = @ARGV;
+
+sub matches {
+    my ($s, $t) = @_;
+
+    return 1 if $t == length($T);
+
+    my $matches = 0;
+
+    my $c = substr($T, $t, 1);
+    foreach my $i ($s .. length($S)-1) {
+        if ($c eq substr($S, $i, 1)) {
+            $matches += matches($i+1, $t+1);
+        }
+    }
+
+    return $matches;
+}
+
+say matches(0, 0);