AoC 2025 Day 2 - java

Author: pareronia

README.md

@@ -9,7 +9,7 @@
 | | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
 | ---| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
 | python3 | [✓](src/main/python/AoC2025_01.py) | [✓](src/main/python/AoC2025_02.py) |  |  |  |  |  |  |  |  |  |  |
-| java | [✓](src/main/java/AoC2025_01.java) |  |  |  |  |  |  |  |  |  |  |  |
+| java | [✓](src/main/java/AoC2025_01.java) | [✓](src/main/java/AoC2025_02.java) |  |  |  |  |  |  |  |  |  |  |
 | bash | [✓](src/main/bash/AoC2025_01.sh) |  |  |  |  |  |  |  |  |  |  |  |
 <!-- @END:ImplementationsTable:2025@ -->
 

src/main/java/AoC2025_02.java

@@ -0,0 +1,74 @@
+import com.github.pareronia.aoc.StringOps;
+import com.github.pareronia.aoc.StringOps.StringSplit;
+import com.github.pareronia.aoc.solution.Sample;
+import com.github.pareronia.aoc.solution.Samples;
+import com.github.pareronia.aoc.solution.SolutionBase;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.LongStream;
+
+@SuppressWarnings({"PMD.ClassNamingConventions", "PMD.NoPackage"})
+public final class AoC2025_02 extends SolutionBase<List<AoC2025_02.Range>, Long, Long> {
+
+    private AoC2025_02(final boolean debug) {
+        super(debug);
+    }
+
+    public static AoC2025_02 create() {
+        return new AoC2025_02(false);
+    }
+
+    public static AoC2025_02 createDebug() {
+        return new AoC2025_02(true);
+    }
+
+    @Override
+    protected List<Range> parseInput(final List<String> inputs) {
+        return Arrays.stream(inputs.getFirst().split(","))
+                .map(
+                        s -> {
+                            final StringSplit sp = StringOps.splitOnce(s, "-");
+                            return new Range(Long.parseLong(sp.left()), Long.parseLong(sp.right()));
+                        })
+                .toList();
+    }
+
+    private long solve(final List<Range> ranges, final String pattern) {
+        final Pattern regex = Pattern.compile(pattern);
+        return ranges.stream()
+                .flatMapToLong(
+                        range ->
+                                LongStream.rangeClosed(range.from, range.to)
+                                        .filter(n -> regex.matcher(String.valueOf(n)).matches()))
+                .sum();
+    }
+
+    @Override
+    public Long solvePart1(final List<Range> ranges) {
+        return this.solve(ranges, "^(\\d+)\\1$");
+    }
+
+    @Override
+    public Long solvePart2(final List<Range> ranges) {
+        return this.solve(ranges, "^(\\d+)\\1+$");
+    }
+
+    @Samples({
+        @Sample(method = "part1", input = TEST, expected = "1227775554"),
+        @Sample(method = "part2", input = TEST, expected = "4174379265"),
+    })
+    public static void main(final String[] args) throws Exception {
+        create().run();
+    }
+
+    private static final String TEST =
+            """
+            11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,\
+            446443-446449,38593856-38593862,565653-565659,824824821-824824827,\
+            2121212118-2121212124
+            """;
+
+    record Range(long from, long to) {}
+}