aoc 2024 day 11

adventofcode/README.md

@@ -1422,7 +1422,7 @@
 [20232402tests]: src/test/java/org/ck/adventofcode/year2023/Day24Test.java
 [20232501tests]: src/test/java/org/ck/adventofcode/year2023/Day25Test.java
 
-# 2024 (20/49)
+# 2024 (22/49)
 
 |        # | Name                                              | Solution                             | Test                              |
 |---------:|---------------------------------------------------|:------------------------------------:|:---------------------------------:|
@@ -1446,8 +1446,8 @@
 | 20240902 | [Day 9: Disk Fragmenter - Part 2][20240902]       | ✅[💾][20240902solution] | ✅[💾][20240902tests] |
 | 20241001 | [Day 10: Hoof It][20241001]                       | ✅[💾][20241001solution] | ✅[💾][20241001tests] |
 | 20241002 | [Day 10: Hoof It - Part 2][20241002]              | ✅[💾][20241002solution] | ✅[💾][20241002tests] |
-| 20241101 | [Day 11: ?][20241101]                             | [💾][20241101solution]        | [💾][20241101tests]        |
-| 20241102 | [Day 11: ? - Part 2][20241102]                    | [💾][20241102solution]        | [💾][20241102tests]        |
+| 20241101 | [Day 11: Plutonian Pebbles][20241101]             | ✅[💾][20241101solution] | ✅[💾][20241101tests] |
+| 20241102 | [Day 11: Plutonian Pebbles - Part 2][20241102]    | ✅[💾][20241102solution] | ✅[💾][20241102tests] |
 | 20241201 | [Day 12: ?][20241201]                             | [💾][20241201solution]        | [💾][20241201tests]        |
 | 20241202 | [Day 12: ? - Part 2][20241202]                    | [💾][20241202solution]        | [💾][20241202tests]        |
 | 20241301 | [Day 13: ?][20241301]                             | [💾][20241301solution]        | [💾][20241301tests]        |

adventofcode/src/main/java/org/ck/adventofcode/year2024/Day11.java

@@ -1,34 +1,75 @@
 package org.ck.adventofcode.year2024;
 
-import java.util.Scanner;
+import java.util.*;
 import org.ck.adventofcode.util.AOCSolution;
 import org.ck.codechallengelib.annotation.Solution;
 
 @Solution(
     id = 20241101,
-    name = "Day 11: ?",
+    name = "Day 11: Plutonian Pebbles",
     url = "https://adventofcode.com/2024/day/11",
-    category = "2024",
-    solved = false)
+    category = "2024")
 @Solution(
     id = 20241102,
-    name = "Day 11: ? - Part 2",
+    name = "Day 11: Plutonian Pebbles - Part 2",
     url = "https://adventofcode.com/2024/day/11#part2",
-    category = "2024",
-    solved = false)
+    category = "2024")
 public class Day11 extends AOCSolution {
 
   @Override
   protected void runPartOne(final Scanner in) {
-    run(in);
+    run(in, 25);
   }
 
   @Override
   protected void runPartTwo(final Scanner in) {
-    run(in);
+    run(in, 75);
   }
 
-  private void run(final Scanner in) {
-    print("Whoopsie");
+  private void run(final Scanner in, final int steps) {
+    final List<Long> numbers =
+        Arrays.stream(in.nextLine().split(" ")).map(Long::parseLong).toList();
+
+    final Map<String, Long> cache = new HashMap<>();
+    long sum = 0;
+
+    for (Long number : numbers) {
+      sum += getValueAfterSteps(cache, number, steps);
+    }
+
+    print(sum);
+  }
+
+  private long getValueAfterSteps(
+      final Map<String, Long> cache, final Long number, final int steps) {
+    final String key = "%d-%d".formatted(number, steps);
+    if (cache.containsKey(key)) {
+      return cache.get(key);
+    }
+
+    if (steps == 0) {
+      return 1;
+    }
+
+    long value = 0;
+
+    if (number == 0) {
+      value += getValueAfterSteps(cache, 1L, steps - 1);
+    } else {
+      final String baseTen = String.valueOf(number);
+
+      if (baseTen.length() % 2 == 0) {
+        value +=
+            getValueAfterSteps(
+                    cache, Long.valueOf(baseTen.substring(0, baseTen.length() / 2)), steps - 1)
+                + getValueAfterSteps(
+                    cache, Long.valueOf(baseTen.substring(baseTen.length() / 2)), steps - 1);
+      } else {
+        value += getValueAfterSteps(cache, number * 2024, steps - 1);
+      }
+    }
+
+    cache.put(key, value);
+    return value;
   }
 }

adventofcode/src/test/java/org/ck/adventofcode/year2024/Day11Test.java

@@ -1,11 +1,9 @@
 package org.ck.adventofcode.year2024;
 
 import org.ck.adventofcode.util.BaseAOCTest;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 
-@Disabled
 class Day11Test extends BaseAOCTest {
   @ParameterizedTest
   @ValueSource(strings = {"01", "01a"})
@@ -14,7 +12,7 @@ void testOne(String name) throws Exception {
   }
 
   @ParameterizedTest
-  @ValueSource(strings = {"02", "02a"})
+  @ValueSource(strings = {"02"})
   void testTwo(String name) throws Exception {
     runTest(new Day11()::partTwo, "day11/%s".formatted(name));
   }

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day11/01.result.txt

@@ -0,0 +1 @@
+222461

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day11/01.txt

@@ -0,0 +1 @@
+2 54 992917 5270417 2514 28561 0 990

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day11/01a.result.txt

@@ -0,0 +1 @@
+55312

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day11/01a.txt

@@ -0,0 +1 @@
+125 17

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day11/02.result.txt

@@ -0,0 +1 @@
+264350935776416

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day11/02.txt

@@ -0,0 +1 @@
+2 54 992917 5270417 2514 28561 0 990