tasks a-s

Task/Roman-numerals-Encode/Java/roman-numerals-encode.java

@@ -0,0 +1,41 @@
+public class RN {
+
+    enum Numeral {
+        I(1), IV(4), V(5), IX(9), X(10), XL(40), L(50), XC(90), C(100), CD(400), D(500), CM(900), M(1000);
+        int weight;
+
+        Numeral(int weight) {
+            this.weight = weight;
+        }
+    };
+
+    public static String roman(long n) {
+
+        if( n <= 0) {
+            throw new IllegalArgumentException();
+        }
+
+        StringBuilder buf = new StringBuilder();
+
+        final Numeral[] values = Numeral.values();
+        for (int i = values.length - 1; i >= 0; i--) {
+            while (n >= values[i].weight) {
+                buf.append(values[i]);
+                n -= values[i].weight;
+            }
+        }
+        return buf.toString();
+    }
+
+    public static void test(long n) {
+        System.out.println(n + " = " + roman(n));
+    }
+
+    public static void main(String[] args) {
+        test(1999);
+        test(25);
+        test(944);
+        test(0);
+    }
+
+}