feat: kata/rot13-1 (#809)

* docs: kata description

* feat: kata/rot13-1

---------

Co-authored-by: ParanoidUser <5120290+ParanoidUser@users.noreply.github.com>

Author: github-actions[bot]

kata/5-kyu/index.md

@@ -39,6 +39,7 @@
 - [Primes in numbers](primes-in-numbers "54d512e62a5e54c96200019e")
 - [Product of consecutive Fib numbers](product-of-consecutive-fib-numbers "5541f58a944b85ce6d00006a")
 - [RGB To Hex Conversion](rgb-to-hex-conversion "513e08acc600c94f01000001")
+- [Rot13](rot13-1 "530e15517bc88ac656000716")
 - [ROT13](rot13 "52223df9e8f98c7aa7000062")
 - [Scramblies](scramblies "55c04b4cc56a697bb0000048")
 - [Simple Pig Latin](simple-pig-latin "520b9d2ad5c005041100000f")

kata/5-kyu/rot13-1/README.md

@@ -0,0 +1,8 @@
+# [Rot13](https://www.codewars.com/kata/rot13-1 "https://www.codewars.com/kata/530e15517bc88ac656000716")
+
+ROT13 is a simple letter substitution cipher that replaces a letter with the letter 13 letters after it in the alphabet. ROT13 is an example
+of the Caesar cipher.
+
+Create a function that takes a string and returns the string ciphered with Rot13.
+If there are numbers or special characters included in the string, they should be returned as they are. Only letters from the latin/english
+alphabet should be shifted, like in the original Rot13 "implementation".

kata/5-kyu/rot13-1/main/Kata.java

@@ -0,0 +1,9 @@
+import static java.util.stream.Collectors.joining;
+
+interface Kata {
+  static String rot13(String str) {
+    return str.chars().mapToObj(c -> "" + (char) c)
+        .map(c -> "" + (char) (c.charAt(0) + (c.matches("(?i)[A-M]") ? 13 : c.matches("(?i)[N-Z]") ? -13 : 0)))
+        .collect(joining());
+  }
+}

kata/5-kyu/rot13-1/test/SolutionTest.java

@@ -0,0 +1,16 @@
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+class SolutionTest {
+  @ParameterizedTest
+  @CsvSource(textBlock = """
+      test, grfg
+      Test, Grfg
+      !@#$, !@#$
+      """)
+  void sample(String message, String expected) {
+    assertEquals(expected, Kata.rot13(message));
+  }
+}