day06 for AoC 2023 (part 1)

Took 23 minutes

Author: albertominetti

src/main/java/aminetti/adventofcode2024/day06/Day06.java

@@ -0,0 +1,86 @@
+package aminetti.adventofcode2024.day06;
+
+import aminetti.adventofcode2023.day17.Day17;
+import org.apache.commons.lang3.tuple.ImmutablePair;
+import org.apache.commons.lang3.tuple.Pair;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static aminetti.adventofcode2024.day06.Day06.Direction.*;
+
+public class Day06 {
+    private static final Logger LOGGER = LoggerFactory.getLogger(Day06.class);
+    private List<String> input;
+    private int ROWS;
+    private int COLS;
+
+    public Day06() {
+    }
+
+    public void parseInput(List<String> input) {
+        this.input = input;
+        ROWS = input.size();
+        COLS = input.getFirst().length();
+    }
+
+    public long solvePart1() {
+        Pair<Integer, Integer> start = findStart();
+        Set<Pair<Integer, Integer>> steps = new HashSet<>();
+
+        Pair<Integer, Integer> current = start;
+        Direction d = UP;
+
+        while (inMap(current)) {
+            steps.add(current);
+
+            Pair<Integer, Integer> next = new ImmutablePair<>(current.getLeft() + d.x, current.getRight() + d.y);
+
+            if (inMap(next) && input.get(next.getLeft()).charAt(next.getRight()) == '#') {
+                LOGGER.info("Can't go {}, so rotating 90°", d);
+                d = Direction.values()[(d.ordinal() + 1) % 4];
+                next = new ImmutablePair<>(current.getLeft() + d.x, current.getRight() + d.y);
+            }
+
+            current = next;
+            LOGGER.info("Now position is {}", current);
+        }
+
+        return steps.size();
+    }
+
+    public enum Direction {
+        RIGHT(0, 1), DOWN(1, 0), LEFT(0, -1), UP(-1, 0);
+
+        public final int x;
+        public final int y;
+
+        Direction(int x, int y) {
+            this.x = x;
+            this.y = y;
+        }
+    }
+
+    private boolean inMap(Pair<Integer, Integer> p) {
+        return 0 <= p.getLeft() && p.getLeft() < ROWS && 0 <= p.getRight() && p.getRight() < COLS;
+    }
+
+    private Pair<Integer, Integer> findStart() {
+        for (int i = 0; i < ROWS; i++) {
+            for (int j = 0; j < COLS; j++) {
+                if (input.get(i).charAt(j) == '^') {
+                    return new ImmutablePair<>(i, j);
+                }
+            }
+        }
+        throw new IllegalArgumentException("Can't find start");
+    }
+
+    public long solvePart2() {
+
+        return 0;
+    }
+}

src/test/java/aminetti/adventofcode2024/day06/Day06Test.java

@@ -0,0 +1,73 @@
+package aminetti.adventofcode2024.day06;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.util.List;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.apache.commons.io.IOUtils.readLines;
+import static org.apache.commons.io.IOUtils.resourceToString;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+
+class Day06Test {
+
+    @Test
+    void actualInputPart1() throws IOException {
+        // given
+        List<String> input = readLines(resourceToString("/day06/day06_input.txt", UTF_8));
+
+        // when
+        Day06 solver = new Day06();
+        solver.parseInput(input);
+        long l = solver.solvePart1();
+
+        // then
+        assertThat(l, is(0L));
+    }
+
+    @Test
+    void testInputPart1() throws IOException {
+        // given
+        List<String> input = readLines(resourceToString("/day06/day06_input_test.txt", UTF_8));
+
+        // when
+        Day06 solver = new Day06();
+        solver.parseInput(input);
+        long l = solver.solvePart1();
+
+        // then
+        assertThat(l, is(41L));
+    }
+
+    @Test
+    void actualInputPart2() throws IOException {
+        // given
+        List<String> input = readLines(resourceToString("/day06/day06_input.txt", UTF_8));
+
+        // when
+        Day06 solver = new Day06();
+        solver.parseInput(input);
+        long l = solver.solvePart2();
+
+        // then
+        assertThat(l, is(0L));
+    }
+
+    @Test
+    void testInputPart2() throws IOException {
+        // given
+        List<String> input = readLines(resourceToString("/day06/day06_input_test.txt", UTF_8));
+
+        // when
+        Day06 solver = new Day06();
+        solver.parseInput(input);
+        long l = solver.solvePart2();
+
+        // then
+        assertThat(l, is(0L));
+    }
+
+
+}

src/test/resources/day06/day06_input_test.txt

@@ -0,0 +1,10 @@
+....#.....
+.........#
+..........
+..#.......
+.......#..
+..........
+.#..^.....
+........#.
+#.........
+......#...