aoc 2024 day 13

adventofcode/README.md

@@ -1430,7 +1430,7 @@
 [20232402tests]: src/test/java/org/ck/adventofcode/year2023/Day24Test.java
 [20232501tests]: src/test/java/org/ck/adventofcode/year2023/Day25Test.java
 
-# 2024 (24/49)
+# 2024 (26/49)
 
 |        # | Name                                              | Solution                             | Test                              |
 |---------:|---------------------------------------------------|:------------------------------------:|:---------------------------------:|
@@ -1458,8 +1458,8 @@
 | 20241102 | [Day 11: Plutonian Pebbles - Part 2][20241102]    | ✅[💾][20241102solution] | ✅[💾][20241102tests] |
 | 20241201 | [Day 12: Garden Groups][20241201]                 | ✅[💾][20241201solution] | ✅[💾][20241201tests] |
 | 20241202 | [Day 12: Garden Groups - Part 2][20241202]        | ✅[💾][20241202solution] | ✅[💾][20241202tests] |
-| 20241301 | [Day 13: ?][20241301]                             | [💾][20241301solution]        | [💾][20241301tests]        |
-| 20241302 | [Day 13: ? - Part 2][20241302]                    | [💾][20241302solution]        | [💾][20241302tests]        |
+| 20241301 | [Day 13: Claw Contraption][20241301]              | ✅[💾][20241301solution] | ✅[💾][20241301tests] |
+| 20241302 | [Day 13: Claw Contraption - Part 2][20241302]     | ✅[💾][20241302solution] | ✅[💾][20241302tests] |
 | 20241401 | [Day 14: ?][20241401]                             | [💾][20241401solution]        | [💾][20241401tests]        |
 | 20241402 | [Day 14: ? - Part 2][20241402]                    | [💾][20241402solution]        | [💾][20241402tests]        |
 | 20241501 | [Day 15: ?][20241501]                             | [💾][20241501solution]        | [💾][20241501tests]        |

adventofcode/src/main/java/org/ck/adventofcode/year2024/Day13.java

@@ -1,34 +1,98 @@
 package org.ck.adventofcode.year2024;
 
-import java.util.Scanner;
+import java.util.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import org.ck.adventofcode.util.AOCSolution;
 import org.ck.codechallengelib.annotation.Solution;
 
 @Solution(
     id = 20241301,
-    name = "Day 13: ?",
+    name = "Day 13: Claw Contraption",
     url = "https://adventofcode.com/2024/day/13",
-    category = "2024",
-    solved = false)
+    category = "2024")
 @Solution(
     id = 20241302,
-    name = "Day 13: ? - Part 2",
+    name = "Day 13: Claw Contraption - Part 2",
     url = "https://adventofcode.com/2024/day/13#part2",
-    category = "2024",
-    solved = false)
+    category = "2024")
 public class Day13 extends AOCSolution {
+  private static final Pattern BUTTON_PATTERN =
+      Pattern.compile("Button [AB]: X\\+(?<xAmount>\\d+), Y\\+(?<yAmount>\\d+)");
+  private static final Pattern PRICE_PATTERN =
+      Pattern.compile("Prize: X=(?<xPosition>\\d+), Y=(?<yPosition>\\d+)");
 
   @Override
   protected void runPartOne(final Scanner in) {
-    run(in);
+    run(in, 0);
   }
 
   @Override
   protected void runPartTwo(final Scanner in) {
-    run(in);
+    run(in, 10000000000000L);
   }
 
-  private void run(final Scanner in) {
-    print("Whoopsie");
+  private void run(final Scanner in, final long coordinateOffset) {
+    List<Machine> machines = new ArrayList<>();
+
+    while (in.hasNextLine()) {
+      final Button aButton = getButton(in.nextLine(), 3);
+      final Button bButton = getButton(in.nextLine(), 1);
+      final Coordinate priceLocation = getPriceLocation(in.nextLine(), coordinateOffset);
+      if (in.hasNextLine()) {
+        in.nextLine();
+      }
+
+      machines.add(new Machine(aButton, bButton, priceLocation));
+    }
+
+    print(machines.stream().mapToLong(this::getMinCoins2).sum());
   }
+
+  private long getMinCoins2(Machine machine) {
+    final long pX = machine.priceLocation().x();
+    final long pY = machine.priceLocation().y();
+    final long aX = machine.a().movementAmount().x();
+    final long aY = machine.a().movementAmount().y();
+    final long bX = machine.b().movementAmount().x();
+    final long bY = machine.b().movementAmount().y();
+
+    final long a = (pX * bY - bX * pY) / (aX * bY - bX * aY);
+    final long b = (pX - a * aX) / bX;
+
+    if (a * aX + b * bX == pX && a * aY + b * bY == pY) {
+      return a * machine.a().coins() + b * machine.b().coins();
+    }
+
+    return 0;
+  }
+
+  private Coordinate getPriceLocation(final String line, final long coordinateOffset) {
+    final Matcher matcher = PRICE_PATTERN.matcher(line);
+    if (matcher.find()) {
+      return new Coordinate(
+          Long.parseLong(matcher.group("xPosition")) + coordinateOffset,
+          Long.parseLong(matcher.group("yPosition")) + coordinateOffset);
+    }
+
+    throw new IllegalArgumentException("Invalid price location: " + line);
+  }
+
+  private Button getButton(final String line, final long coins) {
+    final Matcher matcher = BUTTON_PATTERN.matcher(line);
+    if (matcher.find()) {
+      return new Button(
+          new Coordinate(
+              Long.parseLong(matcher.group("xAmount")), Long.parseLong(matcher.group("yAmount"))),
+          coins);
+    }
+
+    throw new IllegalArgumentException("Invalid button: " + line);
+  }
+
+  private record Coordinate(long x, long y) {}
+
+  private record Button(Coordinate movementAmount, long coins) {}
+
+  private record Machine(Button a, Button b, Coordinate priceLocation) {}
 }

adventofcode/src/test/java/org/ck/adventofcode/year2024/Day13Test.java

@@ -1,21 +1,30 @@
 package org.ck.adventofcode.year2024;
 
 import org.ck.adventofcode.util.BaseAOCTest;
-import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 
-@Disabled
 class Day13Test extends BaseAOCTest {
   @ParameterizedTest
-  @ValueSource(strings = {"01", "01a"})
+  @ValueSource(strings = {"01a"})
   void testOne(String name) throws Exception {
     runTest(new Day13()::partOne, "day13/%s".formatted(name));
   }
 
+  @Test
+  void testOne() throws Exception {
+    runEncryptedTest(new Day13()::partOne, "day13/01");
+  }
+
   @ParameterizedTest
-  @ValueSource(strings = {"02", "02a"})
+  @ValueSource(strings = {"02a"})
   void testTwo(String name) throws Exception {
     runTest(new Day13()::partTwo, "day13/%s".formatted(name));
   }
+
+  @Test
+  void testTwo() throws Exception {
+    runEncryptedTest(new Day13()::partTwo, "day13/02");
+  }
 }

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day13/01.result.txt

@@ -0,0 +1 @@
+37686

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day13/01a.result.txt

@@ -0,0 +1 @@
+480

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day13/01a.txt

@@ -0,0 +1,15 @@
+Button A: X+94, Y+34
+Button B: X+22, Y+67
+Prize: X=8400, Y=5400
+
+Button A: X+26, Y+66
+Button B: X+67, Y+21
+Prize: X=12748, Y=12176
+
+Button A: X+17, Y+86
+Button B: X+84, Y+37
+Prize: X=7870, Y=6450
+
+Button A: X+69, Y+23
+Button B: X+27, Y+71
+Prize: X=18641, Y=10279

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day13/02.result.txt

@@ -0,0 +1 @@
+77204516023437

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day13/02a.result.txt

@@ -0,0 +1 @@
+875318608908

adventofcode/src/test/resources/org/ck/adventofcode/year2024/day13/02a.txt

@@ -0,0 +1,15 @@
+Button A: X+94, Y+34
+Button B: X+22, Y+67
+Prize: X=8400, Y=5400
+
+Button A: X+26, Y+66
+Button B: X+67, Y+21
+Prize: X=12748, Y=12176
+
+Button A: X+17, Y+86
+Button B: X+84, Y+37
+Prize: X=7870, Y=6450
+
+Button A: X+69, Y+23
+Button B: X+27, Y+71
+Prize: X=18641, Y=10279