kata/weird-ipv6-hex-string-parsing

Author: ParanoidUser

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

@@ -2,19 +2,20 @@
 
 ## 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.
+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.
+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
-```
-
-Happy coding!
+```

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

@@ -0,0 +1,8 @@
+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

@@ -0,0 +1,20 @@
+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));
+  }
+}