aoc 2017 day 10

adventofcode/README.md

@@ -406,7 +406,7 @@
 [20162402tests]: src/test/java/org/ck/adventofcode/year2016/Day24Test.java
 [20162501tests]: src/test/java/org/ck/adventofcode/year2016/Day25Test.java
 
-# 2017 (18/18)
+# 2017 (20/20)
 
 |        # | Name                                                                | Solution                             | Test                              |
 |---------:|---------------------------------------------------------------------|:------------------------------------:|:---------------------------------:|
@@ -428,6 +428,8 @@
 | 20170802 | [Day 8: I Heard You Like Registers - Part 2][20170802]              | ✅[💾][20170802solution] | ✅[💾][20170802tests] |
 | 20170901 | [Day 9: Stream Processing][20170901]                                | ✅[💾][20170901solution] | ✅[💾][20170901tests] |
 | 20170902 | [Day 9: Stream Processing - Part 2][20170902]                       | ✅[💾][20170902solution] | ✅[💾][20170902tests] |
+| 20171001 | [Day 10: Knot Hash][20171001]                                       | ✅[💾][20171001solution] | ✅[💾][20171001tests] |
+| 20171002 | [Day 10: Knot Hash - Part 2][20171002]                              | ✅[💾][20171002solution] | ✅[💾][20171002tests] |
 
 [20170101]: https://adventofcode.com/2017/day/1
 [20170102]: https://adventofcode.com/2017/day/1#part2
@@ -447,6 +449,8 @@
 [20170802]: https://adventofcode.com/2017/day/8#part2
 [20170901]: https://adventofcode.com/2017/day/9
 [20170902]: https://adventofcode.com/2017/day/9#part2
+[20171001]: https://adventofcode.com/2017/day/10
+[20171002]: https://adventofcode.com/2017/day/10#part2
 
 [20170101solution]: src/main/java/org/ck/adventofcode/year2017/Day01.java
 [20170102solution]: src/main/java/org/ck/adventofcode/year2017/Day01.java
@@ -466,6 +470,8 @@
 [20170802solution]: src/main/java/org/ck/adventofcode/year2017/Day08.java
 [20170901solution]: src/main/java/org/ck/adventofcode/year2017/Day09.java
 [20170902solution]: src/main/java/org/ck/adventofcode/year2017/Day09.java
+[20171001solution]: src/main/java/org/ck/adventofcode/year2017/Day10.java
+[20171002solution]: src/main/java/org/ck/adventofcode/year2017/Day10.java
 
 [20170101tests]: src/test/java/org/ck/adventofcode/year2017/Day01Test.java
 [20170102tests]: src/test/java/org/ck/adventofcode/year2017/Day01Test.java
@@ -485,6 +491,8 @@
 [20170802tests]: src/test/java/org/ck/adventofcode/year2017/Day08Test.java
 [20170901tests]: src/test/java/org/ck/adventofcode/year2017/Day09Test.java
 [20170902tests]: src/test/java/org/ck/adventofcode/year2017/Day09Test.java
+[20171001tests]: src/test/java/org/ck/adventofcode/year2017/Day10Test.java
+[20171002tests]: src/test/java/org/ck/adventofcode/year2017/Day10Test.java
 
 # 2019 (29/30)
 

adventofcode/src/main/java/org/ck/adventofcode/year2017/Day10.java

@@ -0,0 +1,90 @@
+package org.ck.adventofcode.year2017;
+
+import java.util.Arrays;
+import java.util.HexFormat;
+import java.util.List;
+import java.util.Scanner;
+import java.util.function.Function;
+import org.ck.adventofcode.util.AOCSolution;
+import org.ck.codechallengelib.annotation.Solution;
+
+@Solution(
+    id = 20171001,
+    name = "Day 10: Knot Hash",
+    url = "https://adventofcode.com/2017/day/10",
+    category = "2017")
+@Solution(
+    id = 20171002,
+    name = "Day 10: Knot Hash - Part 2",
+    url = "https://adventofcode.com/2017/day/10#part2",
+    category = "2017")
+public class Day10 extends AOCSolution {
+  @Override
+  protected void runPartOne(final Scanner in) {
+    run(
+        in,
+        line -> Arrays.stream(line.split(",")).map(Integer::valueOf).toList(),
+        1,
+        list -> String.valueOf(list[0] * list[1]));
+  }
+
+  @Override
+  protected void runPartTwo(final Scanner in) {
+    run(
+        in,
+        line -> (line + "\u0011\u001F\u0049\u002F\u0017").chars().boxed().toList(),
+        64,
+        list -> {
+          byte[] bytes = new byte[16];
+
+          for (int i = 0; i < list.length; ++i) {
+            bytes[i / 16] = (byte) (bytes[i / 16] ^ list[i]);
+          }
+
+          return HexFormat.of().formatHex(bytes);
+        });
+  }
+
+  private void run(
+      final Scanner in,
+      final Function<String, List<Integer>> getLengthsFromLine,
+      final int rounds,
+      final Function<int[], String> getResult) {
+    int listLength = in.nextInt();
+    in.nextLine();
+
+    final int[] list = new int[listLength];
+    for (int i = 0; i < listLength; ++i) {
+      list[i] = i;
+    }
+
+    final List<Integer> lengths = getLengthsFromLine.apply(in.nextLine());
+
+    int index = 0;
+    int skipSize = 0;
+
+    for (int round = 0; round < rounds; ++round) {
+      for (int length : lengths) {
+        int start = index;
+        int end = (start + length - 1) % list.length;
+
+        for (int i = 0; i < length / 2; ++i) {
+          final int temp = list[end];
+          list[end] = list[start];
+          list[start] = temp;
+
+          start = (start + 1) % list.length;
+          --end;
+          if (end < 0) {
+            end = list.length - 1;
+          }
+        }
+
+        index = (index + length + skipSize) % list.length;
+        ++skipSize;
+      }
+    }
+
+    print(getResult.apply(list));
+  }
+}

adventofcode/src/test/java/org/ck/adventofcode/util/InputEncrpyter.java

@@ -0,0 +1,9 @@
+package org.ck.adventofcode.util;
+
+import org.ck.codechallengelib.testhelper.EncryptionHelper;
+
+public class InputEncrpyter {
+  public static void main(final String[] args) {
+    System.err.println(EncryptionHelper.encrypt("", System.getenv("AOC_KEY")));
+  }
+}

adventofcode/src/test/java/org/ck/adventofcode/year2017/Day10Test.java

@@ -0,0 +1,19 @@
+package org.ck.adventofcode.year2017;
+
+import org.ck.adventofcode.util.BaseAOCTest;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+class Day10Test extends BaseAOCTest {
+  @ParameterizedTest
+  @ValueSource(strings = {"01a"})
+  void testPartOneExamples(final String name) throws Exception {
+    runTest(new Day10()::partOne, "day10/%s".formatted(name));
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"02a", "02b", "02a", "02d"})
+  void testPartTwoExamples(final String name) throws Exception {
+    runTest(new Day10()::partTwo, "day10/%s".formatted(name));
+  }
+}

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/01.result.txt

@@ -0,0 +1 @@
+13760

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/01.txt

@@ -0,0 +1 @@
+Sp2J3XSDZaHV5lGMWljz7A==@IualT0OEWhIGJaiZllRKpuZr2J4d+wMZXgPgrShm21UNdLRp5qyMEpfxfwGgTjouNrl2DSgIBqvhf7Hga6lxhwd4kVrc2Q==

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/01a.result.txt

@@ -0,0 +1 @@
+12

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/01a.txt

@@ -0,0 +1,2 @@
+5
+3,4,1,5

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02.result.txt

@@ -0,0 +1 @@
+2da93395f1a6bb3472203252e3b17fe5

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02.txt

@@ -0,0 +1 @@
+Sp2J3XSDZaHV5lGMWljz7A==@IualT0OEWhIGJaiZllRKpuZr2J4d+wMZXgPgrShm21UNdLRp5qyMEpfxfwGgTjouNrl2DSgIBqvhf7Hga6lxhwd4kVrc2Q==

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02a.result.txt

@@ -0,0 +1 @@
+a2582a3a0e66e6e86e3812dcb672a272

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02a.txt

@@ -0,0 +1,2 @@
+256
+

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02b.result.txt

@@ -0,0 +1 @@
+33efeb34ea91902bb2f59c9920caa6cd

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02b.txt

@@ -0,0 +1,2 @@
+256
+AoC 2017

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02c.result.txt

@@ -0,0 +1 @@
+3efbe78a8d82f29979031a4aa0b16a9d

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02c.txt

@@ -0,0 +1,2 @@
+256
+1,2,3

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02d.result.txt

@@ -0,0 +1 @@
+63960835bcdc130f0b66d7ff4f6a5a8e

adventofcode/src/test/resources/org/ck/adventofcode/year2017/day10/02d.txt

@@ -0,0 +1,2 @@
+256
+1,2,4