Day 1

src/main/java/de/advent_of_code_2025/one/Main.java

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+package de.advent_of_code_2025.one;
+
+import de.advent_of_code_2025.util.InputReader;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class Main {
+
+    private static enum Direction {
+        LEFT, RIGHT;
+    }
+
+    private static final class DialPosition {
+        private final int value;
+        private DialPosition next;
+        private DialPosition previous;
+
+        public DialPosition(int value) {
+            this.value = value;
+        }
+
+        public void setNext(DialPosition next) {
+            this.next = next;
+        }
+
+        public void setPrevious(DialPosition previous) {
+            this.previous = previous;
+        }
+
+        public DialPosition next() {
+            return this.next;
+        }
+
+        public DialPosition previous() {
+            return this.previous;
+        }
+
+        public boolean isZero() {
+            return this.value == 0;
+        }
+    }
+
+    private static final class Dial {
+        private DialPosition current;
+        private DialPosition reset;
+
+        public Dial(DialPosition current) {
+            this.current = current;
+            this.reset = current;
+        }
+
+        public int dialEnd(Direction direction, int moves) {
+            if(direction == Direction.LEFT) {
+                for(int i = 0; i < moves; i++) {
+                    this.current = this.current.previous();
+                }
+            }
+            else {
+                for(int i = 0; i < moves; i++) {
+                    this.current = this.current.next();
+                }
+            }
+
+            return this.current.isZero() ? 1 : 0;
+        }
+
+        public int dialAll(Direction direction, int moves) {
+            int zeroCounter = 0;
+
+            if(direction == Direction.LEFT) {
+                for(int i = 0; i < moves; i++) {
+                    this.current = this.current.previous();
+
+                    if(this.current.isZero()) {
+                        zeroCounter += 1;
+                    }
+                }
+            }
+            else {
+                for(int i = 0; i < moves; i++) {
+                    this.current = this.current.next();
+
+                    if(this.current.isZero()) {
+                        zeroCounter += 1;
+                    }
+                }
+            }
+
+            return zeroCounter;
+        }
+
+        public void reset() {
+            this.current = this.reset;
+        }
+    }
+
+    private static final record Command(Direction direction, int moves) {
+        public int apply(Dial dial) {
+            return dial.dialEnd(this.direction, this.moves);
+        }
+
+        public int applyAll(Dial dial) {
+            return dial.dialAll(this.direction, this.moves);
+        }
+    }
+
+    public static void main(String[] args) throws Throwable {
+        final List<String> lines = InputReader.read(args);
+        final DialPosition start = setupDialPositions();
+        final Dial dial = new Dial(start);
+        final List<Command> commands = setupCommands(lines);
+        int zeroCounter = 0;
+        int zeroCounterAll = 0;
+
+        // Part 1
+
+        for (Command c : commands) {
+            zeroCounter += c.apply(dial);
+        }
+
+        System.out.println(zeroCounter);
+
+        // Part 2
+
+        dial.reset();
+
+        for (Command c : commands) {
+            zeroCounterAll += c.applyAll(dial);
+        }
+
+        System.out.println(zeroCounterAll);
+    }
+
+    private static final List<Command> setupCommands(List<String> lines) {
+        return lines.stream().map(line -> {
+            Direction direction = Direction.RIGHT;
+            int moves = 0;
+
+            if (line.startsWith("L")) {
+                direction = Direction.LEFT;
+            }
+
+            moves = Integer.parseInt(line.substring(1));
+
+            return new Command(direction, moves);
+        }).collect(Collectors.toList());
+    }
+
+    private static final DialPosition setupDialPositions() {
+        final List<DialPosition> positions = new ArrayList<>(100);
+
+        IntStream.range(0, 100).mapToObj(DialPosition::new).forEach(positions::add);
+
+        DialPosition current = null;
+        DialPosition next = null;
+        DialPosition previous = null;
+
+        for(int i = 0; i < 100; i++) {
+            current = positions.get(i);
+
+            if(i == 0) {
+                next = positions.get(i + 1);
+                previous = positions.getLast();
+            }
+            else if(i == positions.size() - 1) {
+                next = positions.getFirst();
+                previous = positions.get(i - 1);
+            }
+            else {
+                next = positions.get(i + 1);
+                previous = positions.get(i - 1);
+            }
+
+            current.setNext(next);
+            current.setPrevious(previous);
+        }
+
+        return positions.get(50);
+    }
+}

src/main/resources/five/input_example.txt

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+3-5
+10-14
+12-18
+16-20
+
+1

src/main/resources/one/input_example.txt

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+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82