2025 init

exercises/roman-numerals.md

@@ -0,0 +1,49 @@
+# Roman numerals
+
+Any natural number between 0 and 3999 can be represented in *roman numerals* using the following rules:
+
+1. Only symbols *M*, *D*, *C*, *X*, *V*, *I* can be used. Their values are shown below:
+
+    |   M  |  D  |  C  | L  |  X | V | I |
+    |------|-----|-----|----|----|---|---|
+    | 1000 | 500 | 100 | 50 | 10 | 5 | 1 |
+
+2. Symbols M, C, X, I can be repeated consecutively up to three times.
+3. Symbols D, L and V can not be repeated.
+4. When a symbol of lower value of appears to the right of a symbol of equal or higher value, all symbol values are added.
+5. When a symbols of lower value appears to the left of a symbols of higher value, the lower value is subtracted from the higher value. Only symbols C, X, V can be subtracted. Each symbol can be subtracted only once. The subtracted symbol must be one fifth or one tenth of the larger.
+
+*Examples:*
+
+-    1 = I
+-    4 = IV
+-    8 = VIII
+-    9 = IX
+-   14 = XIV
+-   16 = XVI
+-   19 = XIX
+-   99 = XCIX
+-  105 = CV
+- 1001 = MI
+- 2289 = MMCCLXXXIX
+
+Implement the following methods in the `RomanNumeralUtils` class:
+
+```java
+class RomanNumeralUtils {
+
+    public static boolean isValidRomanNumeral(String value) { ... }
+
+    public static int parseRomanNumeral(String numeral) { ... }
+
+    public static String toRomanNumeral(int number) { ... }
+
+}
+```
+
+Use [jqwik](https://jqwik.net/) to create property based tests verifying these three methods. Create the tests before implementing the methods. Document any bugs you found with the help of these tests during the process.
+
+**NOTE:** 
+- Do not use any existing implementation, write your own code. 
+- Use the provided project template as a starting point.
+- In the project you can launch the tests with `mvn test`.