Data commit

Task/Bifid-cipher/Raku/bifid-cipher.raku

@@ -0,0 +1,24 @@
+sub polybius ($text) {
+    my $n = $text.chars.sqrt.narrow;
+    $text.comb.kv.map: { $^v => ($^k % $n, $k div $n).join: ' ' }
+}
+
+sub encrypt ($message, %poly) {
+    %poly.invert.hash{(flat reverse [Z] %poly{$message.comb}».words).batch(2)».reverse».join: ' '}.join
+}
+
+sub decrypt ($message, %poly) {
+   %poly.invert.hash{reverse [Z] (reverse flat %poly{$message.comb}».words».reverse).batch($message.chars)}.join
+}
+
+
+for 'ABCDEFGHIKLMNOPQRSTUVWXYZ', 'ATTACKATDAWN',
+    'BGWKZQPNDSIOAXEFCLUMTHYVR', 'FLEEATONCE',
+    (flat '_', '.', 'A'..'Z', 'a'..'z', 0..9).pick(*).join, 'The invasion will start on the first of January 2023.'.subst(/' '/, '_', :g)
+ -> $polybius, $message {
+    my %polybius = polybius $polybius;
+    say "\nUsing polybius:\n\t" ~ $polybius.comb.batch($polybius.chars.sqrt.narrow).join: "\n\t";
+    say "\n  Message : $message";
+    say "Encrypted : " ~ my $encrypted = encrypt $message, %polybius;
+    say "Decrypted : " ~ decrypt $encrypted, %polybius;
+}