new tasks

Task/Caesar_cipher/Java/caesar_cipher.java

@@ -0,0 +1,26 @@
+public class Cipher {
+	public static void main(String[] args) {
+		String enc = Cipher.encode(
+				"The quick brown fox Jumped over the lazy Dog", 12);
+		System.out.println(enc);
+		System.out.println(Cipher.decode(enc, 12));
+	}
+
+	public static String decode(String enc, int offset) {
+		return encode(enc, -offset);
+	}
+
+	public static String encode(String enc, int offset) {
+		offset = offset % 26 + 26;
+		StringBuilder encoded = new StringBuilder();
+		for (char i : enc.toLowerCase().toCharArray()) {
+			if (Character.isLetter(i)) {
+				int j = (i - 'a' + offset) % 26;
+				encoded.append((char) (j + 'a'));
+			} else {
+				encoded.append(i);
+			}
+		}
+		return encoded.toString();
+	}
+}