feat: kata/weird-ipv6-hex-string-parsing (#850)

* docs: kata description

* kata/weird-ipv6-hex-string-parsing

---------

Co-authored-by: ParanoidUser <[email protected]>

Author: github-actions[bot]

kata/6-kyu/index.md

@@ -431,6 +431,7 @@
 - [VIN Checker](vin-checker "60a54750138eac0031eb98e1")
 - [Wave Sorting](wave-sorting "596f28fd9be8ebe6ec0000c1")
 - [We are the Robots d[(0)(0)]b](we-are-the-robots-d-0-0-b "587ae98e2ab0ef32ef00004c")
+- [Weird IPv6 hex string parsing](weird-ipv6-hex-string-parsing "5f5bc8a04e485f002d85b303")
 - [What century is it?](what-century-is-it "52fb87703c1351ebd200081f")
 - [What's A Name In?](whats-a-name-in "59daf400beec9780a9000045")
 - [What's Your Poison?](whats-your-poison "58c47a95e4eb57a5b9000094")

kata/6-kyu/weird-ipv6-hex-string-parsing/README.md

@@ -0,0 +1,21 @@
+# [Weird IPv6 hex string parsing](https://www.codewars.com/kata/weird-ipv6-hex-string-parsing "https://www.codewars.com/kata/5f5bc8a04e485f002d85b303")
+
+## Description
+
+As the title already told you, you have to parse a IPv6 hex string in a weird way. For each block in the string you have to parse its
+characters as if they were separate hexadecimal values, add them up, and join the results into a string.
+
+Here's an example of an IPv6 string: `1B1D:AF01:3847:F8C4:20E9:0111:DFEA:AAAA`. And here's how you'd convert its first block to an integer:
+`"1B1D" => 0x1 + 0xB + 0x1 + 0xD = 26`. After all the blocks have been processed in the same way, the results should be joined together:
+``"26" + "26" + "22" + "39" + "25" + "3" + "52" + "40"`` -> ``"262622392535240"``
+
+**Note**: some character other than colon (`:`) may be used in the input string, but it is guaranteed that hexadecimal digits will never be
+used as separators.
+
+#### Examples
+
+```
+"1111:1111:1111:1111:1111:1111:1111:1111" => "4" + "4" + "4" + "4" + "4" + "4" + "4" + "4" => "44444444"
+"1111-1111-1111-1111-1111-1111-1111-1111" => "4" + "4" + "4" + "4" + "4" + "4" + "4" + "4" => "44444444"
+"ABCD_1111_ABCD_1111_ABCD_1111_ABCD_1111" => "46" + "4" + "46" + "4" + "46" + "4" + "46" + "4" => 464464464464
+```

kata/6-kyu/weird-ipv6-hex-string-parsing/main/Solution.java

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+import static java.util.stream.Collectors.joining;
+import static java.util.stream.Stream.of;
+
+interface Solution {
+  static String parseIPv6(String ip) {
+    return of(ip.split("[^0-9A-F]")).map(s -> s.chars().map(c -> Character.digit(c, 16)).sum() + "").collect(joining());
+  }
+}

kata/6-kyu/weird-ipv6-hex-string-parsing/test/SolutionTest.java

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+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 = """
+      1234:5678:9ABC:D00F:1111:2222:3333:4445, 10264228481217
+      5454:FBFD:9ABC:AAAA:FFFF:2222:FBDE:0101, 18544240608532
+      0000:0000:0000:0000:0000:0000:0000:0000, 00000000
+      FFFF:FFFF:BBBB:CCCC:1212:AABC:0000:1111, 6060444864304
+      ACDD-0101-9ABC-AAAA-FFFF-2222-FBDE-ACCC, 48242406085346
+      5454rFBFDr9ABCrAA0ArFAFFr2222rFBDEr0101, 18544230558532
+      F234#5678#9ABC#D00F#1111#2222#3333#4485, 24264228481221
+      """)
+  void sample(String ip, String expected) {
+    assertEquals(expected, Solution.parseIPv6(ip));
+  }
+}