Ancient Challenges

1 files changed, 46 insertions, 0 deletions

diff --git a/challenge-018/zapwai/perl/ch-1.pl b/challenge-018/zapwai/perl/ch-1.pl
new file mode 100644
index 0000000000..d9aa2d1a54
--- /dev/null
+++ b/challenge-018/zapwai/perl/ch-1.pl
@@ -0,0 +1,46 @@
+use v5.38;
+if (@ARGV < 2) {
+    say "Please provide two (or more) arguments.";
+    exit;
+}
+
+sub gen_substr($word) {
+    my @subs;
+    my $current_length = 1;
+    my $a = -1;
+    do {
+	$a++;
+	if ($a + $current_length > length $word) {
+	    $a = 0;
+	    $current_length++;
+	}
+	push @subs, substr($word, $a, $current_length);
+    } while ($current_length < length $word);
+    return @subs;
+}
+
+sub common(@list) {
+    my $ans;
+    my @subs;
+    for my $i (0 .. $#list) {
+	push @subs, gen_substr($list[$i]);
+    }
+    my @common;
+    for my $i (0 .. $#subs) {
+	for my $j (0 .. $#subs) {
+	    next if ($i == $j);
+	    push @common, $subs[$i] if ($subs[$i] eq $subs[$j]);
+	}
+    }
+    my $max = 0;
+    my $ans_word;
+    for my $word (@common) {
+	if (length $word > $max) {
+	    $max = length $word;
+	    $ans_word = $word;
+	}
+    }
+    return $ans_word;
+}
+
+say common(@ARGV);