Data commit

Task/Caesar-cipher/Vala/caesar-cipher.vala

@@ -0,0 +1,33 @@
+static void println(string str) {
+    stdout.printf("%s\r\n", str);
+}
+
+static unichar encrypt_char(unichar ch, int code) {
+    if (!ch.isalpha()) return ch;
+
+    unichar offset = ch.isupper() ? 'A' : 'a';
+    return (unichar)((ch + code - offset) % 26 + offset);
+}
+
+static string encrypt(string input, int code) {
+    var builder = new StringBuilder();
+
+    unichar c;
+    for (int i = 0; input.get_next_char(ref i, out c);) {
+        builder.append_unichar(encrypt_char(c, code));
+    }
+
+    return builder.str;
+}
+
+static string decrypt(string input, int code) {
+    return encrypt(input, 26 - code);
+}
+
+const string test_case = "The quick brown fox jumped over the lazy dog";
+
+void main() {
+    println(test_case);
+    println(encrypt(test_case, -1));
+    println(decrypt(encrypt(test_case, -1), -1));
+}