dirty Day2 but clean Maven setup

.gitignore

+### Advent of Code ###
+src/main/resources/day*.input
+
+### Maven ###
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+.idea/
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
\ No newline at end of file

README.md

+Advent of Code 2023
+===================
+
+This year will be in Java.
+
+Requirements
+------------
+
+- Maven
+- Java SDK (21 here but it shouldn't matter)
+
+Build
+-----
+
+    mvn clean install
+
+Usage
+-----
+
+    mvn exec:java -Day=1
+    mvn exec:java -Day=10
+    mvn exec:java
+
+When no day is given, it assumes today.
+
+Contributing
+------------
+
+Write classes `Day1`, ..., `Day10`, ... that extend the abstract class `Day`.
+Most of your work should go to implement the methods `String part1()` and `String part2()`.
+
+The superclass `Day` provides a constructor to fetch the inputs `day1.input1`, ..., `day10.input`, ... 
+from `src/(main|test)/resources`.
+
+In development, you might want to chain the Maven goals:
+
+    mvn clean install exec:java

pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>CieDuVaseDesNoces</groupId>
+    <artifactId>advent-of-code-2023-java</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <exec.mainClass>${project.groupId}.Main</exec.mainClass>
+        <exec.args>${ay}</exec.args>
+        <ay>${maven.build.timestamp}</ay>
+        <maven.build.timestamp.format>d</maven.build.timestamp.format>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>5.8.1</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+</project>
\ No newline at end of file

src/main/java/CieDuVaseDesNoces/Day.java

+package CieDuVaseDesNoces;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.List;
+import java.util.Objects;
+
+import static java.lang.Thread.currentThread;
+
+abstract class Day {
+    List<String> input;
+    Day(String inputName) {
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(
+                Objects.requireNonNull(currentThread().getContextClassLoader()
+                        .getResourceAsStream(inputName))))) {
+            input = reader.lines().toList();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    abstract String part1();
+
+    abstract String part2();
+
+//    public static void main(String[] args) {
+        //final Day today = new Day("1");
+        //System.out.println(part1());
+        //System.out.println(part2());
+
+}

src/main/java/CieDuVaseDesNoces/Day2.java

+package CieDuVaseDesNoces;
+
+import java.util.HashMap;
+
+import static java.lang.Integer.max;
+import static java.lang.Integer.parseInt;
+
+public class Day2 extends Day {
+
+    static HashMap<String, Integer> limit = new HashMap<>(3);
+
+    Day2(String inputName) {
+        super(inputName);
+        limit.put("red", 12);
+        limit.put("green", 13);
+        limit.put("blue", 14);
+    }
+
+    String part1() {
+        int ans = 0;
+        for (String game : input) {
+            String[] tmp = game.split(": ", 2);
+            int gameId = parseInt(tmp[0].split(" ", 2)[1]);
+            boolean possible = true;
+            for (String set : tmp[1].split("; ")) {
+                for (String cubes : set.split(", ")) {
+                    String[] colorQty = cubes.split(" ", 2);
+                    if (parseInt(colorQty[0]) > limit.get(colorQty[1])) {
+                        possible = false;
+                        break;
+                    }
+                }
+                if (!possible) break;
+            }
+            if (possible) ans += gameId;
+        }
+        return String.valueOf(ans);
+    }
+
+    String part2() {
+        int ans = 0;
+        for (String game : input) {
+            String[] tmp = game.split(": ", 2);
+            HashMap<String, Integer> needed = new HashMap<>(3);
+            needed.put("blue", 0);
+            needed.put("red", 0);
+            needed.put("green", 0);
+            for (String set : tmp[1].split("; ")) {
+                for (String cubes : set.split(", ")) {
+                    String[] colorQty = cubes.split(" ", 2);
+                    needed.put(colorQty[1], max(parseInt(colorQty[0]),
+                            needed.get(colorQty[1])));
+                }
+            }
+            int power = 1;
+            for (int col : needed.values()) {
+                power *= col;
+            }
+            if (power == 0) System.err.println(power);
+            ans += power;
+        }
+        return String.valueOf(ans);
+    }
+}

src/main/java/CieDuVaseDesNoces/Main.java

+package CieDuVaseDesNoces;
+
+import java.lang.reflect.InvocationTargetException;
+
+import static java.lang.Integer.parseInt;
+
+public class Main {
+    public static void main(String[] args)
+            throws ClassNotFoundException, NoSuchMethodException,
+            InvocationTargetException, InstantiationException,
+            IllegalAccessException {
+        int day = parseInt(args[0]);
+        if (day < 1 || day > 25) {
+            throw new IllegalArgumentException(
+                    "Day should be between 1 and 25");
+        }
+        Day today =
+                (Day) Class.forName(Main.class.getPackageName() + ".Day" + day)
+                        .getDeclaredConstructor(String.class)
+                        .newInstance("day" + day + ".input");
+        System.out.println(today.part1());
+        System.out.println(today.part2());
+    }
+}

src/test/java/CieDuVaseDesNoces/Day2Test.java

+package CieDuVaseDesNoces;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Day2Test {
+    Day2 today = new Day2("day2.input");
+
+    @Test
+    void part1_test() {
+        assertEquals("8", today.part1());
+    }
+
+    @Test
+    void part2_test() {
+        assertEquals("2286", today.part2());
+    }
+}

src/test/resources/day2.input

+Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green