CDE

Task/Caesar-cipher/D/caesar-cipher-2.d

@@ -0,0 +1,20 @@
+import std.stdio, std.ascii;
+
+void inplaceRot(char[] txt, in int key) pure nothrow {
+    foreach (ref c; txt) {
+        if (isLower(c))
+            c = (c - 'a' + key) % 26 + 'a';
+        else if (isUpper(c))
+            c = (c - 'A' + key) % 26 + 'A';
+    }
+}
+
+void main() {
+    enum key = 3;
+    auto txt = "The five boxing wizards jump quickly".dup;
+    writeln("Original:  ", txt);
+    txt.inplaceRot(key);
+    writeln("Encrypted: ", txt);
+    txt.inplaceRot(26 - key);
+    writeln("Decrypted: ", txt);
+}