AOC 2022 Day 9 flutter

main.dart

import 'dart:async';
import 'dart:math';

import 'package:flutter/material.dart';

// Hack for missing `more` library
extension IntegerRangeExtension on int {
  List<int> to(int end) => List.generate(end - this, (i) => i + this);
}

void main() async {
  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Container(
          color: const Color(0xFF15202D),
          child: const SizedBox.expand(
            child: Rope(),
          ),
        ),
      ),
    ),
  );
}

class RopePainter extends CustomPainter {
  Model model;
  RopePainter(this.model);

  @override
  void paint(Canvas canvas, Size size) {
    var scale = model.maxDim - model.minDim;
    var color = Colors.grey[300]!;
    for (var s in model.anySeen) {
      drawSeed(canvas, 400.0 * (s.x - model.minDim) / scale,
          400.0 * (s.y - model.minDim) / scale, color);
    }
    color = Colors.grey;
    for (var s in model.seen) {
      drawSeed(canvas, 400.0 * (s.x - model.minDim) / scale,
          400.0 * (s.y - model.minDim) / scale, color);
    }
    color = Colors.orange;
    for (var s in model.chain) {
      drawSeed(canvas, 400.0 * (s.x - model.minDim) / scale,
          400.0 * (s.y - model.minDim) / scale, color);
    }
    var s = model.chain.last;
    drawSeed(canvas, 400.0 * (s.x - model.minDim) / scale,
        400.0 * (s.y - model.minDim) / scale, Colors.red);
    s = model.chain.first;
    drawSeed(canvas, 400.0 * (s.x - model.minDim) / scale,
        400.0 * (s.y - model.minDim) / scale, Colors.black);
  }

  @override
  bool shouldRepaint(RopePainter oldDelegate) {
    return true;
    //return oldDelegate.model.chain != model.chain;
  }

  // Draw a small circle representing a seed centered at (x,y).
  void drawSeed(Canvas canvas, double x, double y, Color color) {
    final paint = Paint()
      ..strokeWidth = 2
      ..style = PaintingStyle.fill
      ..color = color;
    canvas.drawCircle(Offset(x, y), 2.0, paint);
  }
}

class Rope extends StatefulWidget {
  const Rope({super.key});

  @override
  State<StatefulWidget> createState() {
    return _RopeState();
  }
}

int segments = 2;

class _RopeState extends State<Rope> {
  Model model;
  late Timer _timer;
  bool _running = false;

  _RopeState() : model = Model(segments);
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text("Planck rope")),
      body: Column(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Container(
            decoration: BoxDecoration(
              border: Border.all(
                color: Colors.transparent,
              ),
            ),
            child: SizedBox(
              width: 400,
              height: 400,
              child: CustomPaint(
                painter: RopePainter(model),
              ),
            ),
          ),
          Text("Step number: ${model.nMove}"),
          Text("Length of rope: $segments"),
          ConstrainedBox(
            constraints: const BoxConstraints.tightFor(width: 300),
            child: Slider.adaptive(
              min: 2,
              max: 100,
              value: segments.toDouble(),
              onChanged: (newValue) {
                setState(() {
                  segments = newValue.toInt();
                });
              },
            ),
          ),
          ElevatedButton(
            onPressed: () {
              toggleTimer();
            },
            child: Text(_running ? "running" : "start"),
          ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    _timer.cancel();
    super.dispose();
  }

  void toggleTimer() {
    setState(() {
      _running = !_running;
      if (_running) model = Model(segments);
    });
    _timer = Timer.periodic(
      const Duration(milliseconds: 10),
      (Timer timer) {
        setState(() {
          if (!_running) {
            timer.cancel();
          } else if (!model.makeMove()) {
            _running = false;
          }
        });
      },
    );
  }
}

class Model {
  List<Point<int>> chain;
  int segments;
  var seen = {const Point(0, 0)};
  var anySeen = {const Point(0, 0)};
  var maxDim = 10;
  var minDim = -10;
  var nMove = 0;

  List<String> moves;
  Model(this.segments)
      : moves = lines.split('\n'),
        chain = List.generate(segments, (index) => const Point(0, 0));

  var dirs = {
    'R': const Point(1, 0),
    'L': const Point(-1, 0),
    'U': const Point(0, 1),
    'D': const Point(0, -1)
  };

  bool makeMove() {
    moveSegment(int ix) {
      var delta = chain[ix - 1] - chain[ix];
      if (delta.x.abs() <= 1 && delta.y.abs() <= 1) return;
      chain[ix] += Point(delta.x.sign, delta.y.sign);
      anySeen.add(chain[ix]);

      maxDim = max(maxDim, chain[ix].x);
      maxDim = max(maxDim, chain[ix].y);
      minDim = min(minDim, chain[ix].x);
      minDim = min(minDim, chain[ix].y);
    }

    var ps = moves[nMove].split(' ');
    for (var _ in 0.to(int.parse(ps.last))) {
      chain[0] += dirs[ps.first]!;
      anySeen.add(chain.first);
      1.to(segments).forEach((ix) => moveSegment(ix));
      seen.add(chain.last);
    }
    nMove += 1;
    return nMove < moves.length;
  }
}

var lines = '''U 2
D 2
L 2
R 2
D 1
L 2
R 1
L 2
U 2
L 1
R 1
L 1
R 1
U 2
D 2
L 1
U 1
L 2
D 1
U 2
D 1
R 1
D 1
U 2
D 2
U 1
R 2
D 2
R 1
U 1
D 1
R 1
L 2
U 2
D 2
L 1
R 2
L 2
R 1
D 1
R 1
D 2
U 2
R 2
D 2
U 2
D 1
U 1
R 2
U 2
R 2
U 2
D 1
U 1
R 2
D 1
U 2
L 1
U 2
D 1
R 2
U 1
R 2
D 1
L 2
R 1
L 1
R 2
U 1
L 1
D 2
L 2
D 1
R 2
D 1
R 2
U 1
D 1
L 1
R 1
L 2
R 1
U 1
D 2
L 1
D 2
R 1
L 1
R 1
U 2
L 2
D 1
U 1
D 2
U 2
R 2
U 2
R 1
U 2
D 1
R 2
D 2
U 1
D 1
R 2
U 1
R 2
L 1
R 1
D 2
U 1
R 3
D 1
R 1
L 3
D 2
R 1
D 1
R 3
L 2
D 2
L 1
U 3
D 3
L 1
D 1
L 3
D 1
U 3
L 1
R 2
U 2
D 1
L 2
D 3
R 1
U 2
L 2
U 1
L 1
U 2
D 2
U 1
L 1
D 3
R 1
D 3
R 1
D 1
U 1
L 2
U 3
D 2
U 1
R 3
D 1
U 3
L 3
U 1
R 2
L 2
R 1
L 1
U 1
L 1
D 2
L 2
U 2
L 1
D 2
R 1
U 2
L 2
R 2
L 1
U 2
L 2
R 3
L 3
D 1
R 3
L 3
D 2
U 3
L 3
D 2
R 2
L 2
D 2
U 2
L 3
R 1
U 2
L 1
D 3
U 2
D 3
L 2
D 3
U 1
D 3
U 3
L 3
D 2
L 3
R 2
D 3
R 1
D 2
U 2
D 1
U 3
D 2
L 2
D 1
R 1
L 2
R 2
L 3
U 3
L 1
D 2
R 1
L 2
D 2
R 1
D 1
L 4
D 2
R 3
U 4
R 4
U 1
D 4
U 4
D 4
U 2
R 3
U 3
R 4
U 3
L 2
R 1
U 4
D 4
R 2
D 4
R 2
U 2
D 1
R 1
L 3
R 2
D 3
R 3
U 1
D 2
R 4
U 1
D 4
R 1
U 1
D 2
U 4
D 3
L 1
D 4
L 2
D 2
R 3
L 1
U 4
L 4
U 3
D 3
L 2
D 3
U 1
R 4
D 3
L 3
D 4
L 1
D 2
U 4
L 2
D 1
R 3
D 4
U 3
D 4
U 2
L 2
R 3
L 4
R 2
L 4
U 3
L 4
D 3
U 4
L 2
U 3
R 2
D 2
U 1
D 2
L 1
R 4
D 3
L 1
D 3
U 2
L 4
D 4
L 4
R 3
L 3
U 2
L 1
R 2
L 4
D 2
L 3
U 3
D 1
L 2
R 3
U 4
R 1
U 3
D 4
L 2
U 2
L 2
R 5
D 5
U 3
R 4
L 4
U 5
D 3
U 2
L 5
U 1
R 3
L 3
U 4
L 3
D 5
U 2
R 1
U 4
R 5
D 2
L 1
U 3
R 5
D 2
U 3
D 5
U 2
D 2
U 2
L 4
U 5
R 4
U 4
L 3
U 5
R 4
L 4
D 5
R 4
D 4
L 2
R 3
L 5
D 3
U 2
D 4
R 1
U 5
R 4
D 1
U 1
L 1
U 3
D 2
U 4
D 3
U 5
R 2
U 5
L 1
R 5
U 5
R 4
D 3
R 1
D 3
U 3
R 1
L 1
D 5
U 4
R 3
D 3
L 2
U 1
L 2
U 5
D 5
U 2
D 4
L 2
D 2
L 1
D 4
U 2
D 4
R 1
U 1
D 4
L 3
D 3
U 2
D 2
L 1
D 5
R 1
L 2
D 5
U 5
L 3
D 1
R 2
L 2
U 1
L 2
D 5
L 1
R 2
D 4
U 6
L 4
R 5
D 4
U 2
R 1
D 4
L 2
R 5
L 6
R 2
U 6
R 5
D 1
U 1
L 6
R 2
L 6
D 3
L 2
R 6
U 6
L 1
D 3
R 1
D 2
R 4
L 4
U 6
L 3
D 1
U 1
L 4
R 3
D 3
R 6
D 3
L 4
R 5
L 5
D 3
U 3
D 6
R 4
D 5
L 2
D 1
R 4
L 6
R 5
U 4
D 5
L 3
D 1
L 6
D 5
L 3
U 3
R 4
L 4
D 6
R 3
L 1
R 1
U 4
D 6
L 3
R 2
D 1
L 2
U 3
D 3
L 5
U 6
L 5
D 5
R 5
U 6
D 2
U 2
R 5
U 6
D 2
R 1
L 3
U 1
L 6
U 1
R 3
L 3
D 4
U 2
R 3
L 1
D 3
R 5
L 2
D 3
L 2
U 6
R 5
U 5
L 1
U 5
L 6
D 4
U 2
L 5
U 3
D 2
U 4
D 4
U 2
R 5
L 4
D 3
R 6
D 1
R 4
U 5
L 7
D 2
R 6
U 4
L 5
D 5
L 2
D 1
R 4
D 6
L 5
D 4
R 7
U 4
D 7
U 4
R 3
L 7
R 7
D 3
R 5
U 2
R 3
D 5
R 5
U 4
D 2
U 5
R 1
U 5
R 5
U 7
R 4
D 6
L 1
U 3
D 4
U 3
D 7
U 2
L 4
D 6
R 7
U 1
L 6
D 4
R 6
D 4
U 5
L 4
D 6
L 5
D 1
L 5
U 3
L 3
U 2
R 6
U 3
D 4
U 4
L 1
D 3
L 3
R 6
U 2
L 3
D 7
L 2
U 7
L 4
U 4
D 7
L 4
D 3
L 3
D 3
U 1
D 5
L 1
R 4
D 7
L 7
D 6
R 3
U 1
R 6
L 4
D 6
R 5
U 7
L 6
R 6
L 3
D 4
U 1
R 2
L 1
R 1
U 4
D 1
L 4
R 2
U 4
R 3
D 1
U 3
R 4
L 2
U 4
L 3
D 7
R 6
U 4
L 4
D 7
R 6
D 7
L 5
R 5
D 7
R 4
D 1
L 6
U 8
L 4
U 2
L 6
R 1
L 5
U 5
D 3
L 8
R 3
L 3
R 5
U 4
R 6
D 4
U 1
L 2
R 8
D 7
U 3
D 4
L 8
U 6
L 5
R 1
U 1
R 4
U 5
D 2
R 2
U 2
L 1
U 8
D 4
R 7
U 3
D 6
R 6
L 3
R 8
D 7
U 2
R 5
L 3
U 1
D 6
R 1
D 3
L 2
U 2
D 8
U 8
L 8
U 5
D 6
U 6
L 6
U 6
D 5
R 8
L 7
D 6
R 1
D 4
L 1
U 7
R 3
L 2
D 6
R 6
D 7
L 6
U 5
R 4
D 7
U 7
D 5
L 4
R 6
D 3
L 6
U 2
D 7
R 7
U 5
D 3
U 2
L 1
D 2
U 4
L 1
R 3
L 6
U 9
D 8
L 3
R 3
D 4
R 3
U 6
L 7
D 8
R 9
D 1
L 3
R 6
D 4
L 3
U 6
L 7
R 7
U 9
L 9
R 7
U 8
R 7
U 7
D 1
L 9
R 6
U 4
D 6
L 8
R 7
D 6
U 5
R 6
D 8
L 2
D 5
R 9
U 9
L 7
U 2
R 7
L 6
U 6
D 5
L 8
D 7
L 8
D 9
R 7
L 5
D 9
L 7
R 2
L 6
R 9
D 8
R 8
U 7
R 4
L 6
R 1
U 9
D 2
R 7
D 5
R 4
D 1
U 7
D 5
R 4
U 2
D 5
L 9
R 6
U 7
D 5
U 4
D 6
L 3
R 6
U 3
R 9
L 9
U 4
D 1
U 3
R 7
D 8
R 9
U 1
R 1
U 4
D 7
R 1
L 1
R 8
D 1
U 1
L 3
U 2
D 6
R 6
L 1
R 9
L 2
D 3
U 8
D 9
U 1
L 10
U 10
D 8
U 9
L 3
R 2
D 3
U 4
L 2
R 10
L 9
U 5
L 5
D 4
L 7
U 1
L 1
R 1
L 7
D 7
U 7
L 3
U 10
R 7
U 9
L 6
R 2
D 9
L 10
D 9
L 9
R 5
L 5
R 8
D 9
R 1
D 6
L 1
U 9
R 3
L 10
D 10
L 5
D 10
R 3
U 7
D 6
U 7
D 3
R 5
D 5
L 6
D 4
U 7
D 7
R 9
U 10
R 4
U 1
R 1
U 8
R 3
U 10
R 6
L 1
U 3
R 9
U 2
D 8
R 5
D 3
R 3
U 9
R 6
L 8
R 2
L 5
R 2
L 10
D 2
L 3
U 1
D 10
L 5
R 10
D 7
L 2
R 7
U 6
D 4
L 8
D 8
U 3
R 2
U 10
D 8
U 7
D 9
U 4
R 9
L 2
R 8
U 9
R 10
U 10
D 8
R 8
U 2
L 7
U 3
L 1
D 7
R 1
U 2
R 8
U 4
D 4
L 2
U 9
L 7
D 7
L 2
R 2
D 9
L 11
U 4
L 3
D 7
U 7
R 6
D 7
U 11
R 4
L 3
R 2
U 9
L 1
U 11
D 7
R 10
D 10
U 7
L 1
U 8
L 2
D 11
L 6
D 1
L 8
D 9
U 9
R 5
L 4
D 7
U 8
L 5
D 3
R 6
L 5
R 7
L 7
D 7
L 10
U 4
L 1
U 9
D 2
R 2
U 4
D 3
R 9
D 11
U 10
L 3
R 9
U 6
L 1
R 9
L 8
U 2
L 3
U 9
D 2
L 4
D 5
U 4
L 5
D 11
L 6
U 10
D 9
U 3
L 9
U 11
D 3
L 7
D 4
L 8
U 5
D 10
L 7
U 10
L 10
U 4
D 10
L 7
R 2
D 3
L 6
R 5
U 11
D 4
U 6
D 9
R 2
L 9
U 9
R 11
U 9
L 10
R 8
L 5
R 2
L 12
R 8
U 10
R 7
D 7
U 3
L 10
U 10
L 11
U 1
R 8
D 4
R 3
D 7
U 9
L 2
R 9
L 8
R 6
L 7
D 11
U 12
D 6
U 7
L 11
D 1
U 9
R 7
L 3
D 3
U 5
R 5
L 3
R 11
L 2
U 9
D 9
R 8
U 7
D 5
L 9
D 2
L 1
R 5
U 9
R 10
U 12
L 9
D 12
R 5
U 2
L 7
R 6
L 1
U 12
L 10
R 11
D 1
L 8
U 6
D 10
R 10
L 1
U 11
D 2
R 6
U 1
R 4
D 1
R 6
U 12
D 1
L 1
U 4
D 4
U 12
D 12
L 5
R 10
D 4
R 1
D 8
U 6
R 7
D 12
U 9
D 6
U 6
D 1
R 2
L 7
R 5
L 4
U 1
L 10
R 8
L 12
D 11
U 2
L 10
D 12
R 9
D 1
U 7
L 5
D 4
U 12
L 12
D 11
U 11
L 6
D 2
R 11
L 1
U 10
L 12
D 11
R 8
D 2
L 10
R 4
L 10
D 13
L 10
D 5
U 9
L 3
D 2
U 3
D 11
L 7
D 11
U 4
D 11
U 8
L 5
U 6
L 3
U 3
R 8
D 10
R 1
D 13
L 7
D 7
R 1
D 2
L 3
D 5
R 5
L 5
U 7
L 4
D 1
L 11
R 10
U 8
D 9
U 8
R 11
L 1
R 6
D 6
U 4
L 2
D 11
U 10
D 4
L 11
R 5
U 2
D 10
U 12
L 12
D 11
L 12
D 10
L 4
U 7
D 1
R 4
L 10
D 9
R 5
D 3
L 3
D 5
R 9
D 10
L 8
R 6
D 4
U 5
R 11
U 13
R 10
U 11
R 9
U 4
D 8
U 4
D 6
R 12
U 12
R 9
U 12
L 13
U 6
D 10
R 2
L 5
U 3
L 8
R 11
D 13
R 6
U 13
L 3
U 3
D 4
L 11
U 14
D 13
U 1
L 8
U 13
R 14
U 2
L 13
R 1
U 1
L 13
R 4
D 10
R 10
D 14
R 7
D 10
L 2
R 7
U 10
R 13
D 7
U 11
D 13
L 7
U 8
L 4
D 7
L 2
R 2
L 7
D 13
U 2
R 10
U 2
L 6
R 11
D 11
L 13
D 13
L 14
R 4
L 7
D 7
R 11
U 10
D 3
R 4
L 2
R 9
U 7
L 1
R 5
L 3
U 8
R 6
U 10
L 3
R 12
U 13
D 3
R 7
D 1
U 7
R 13
D 1
R 10
L 8
R 8
L 4
R 9
L 5
D 13
L 3
U 8
L 13
U 4
R 3
U 2
R 7
D 9
R 5
U 4
R 5
D 7
L 14
R 13
D 3
L 12
D 7
U 5
L 8
D 10
U 14
D 8
R 12
U 3
L 9
R 7
U 9
R 5
L 6
U 13
R 6
L 8
R 12
D 13
U 6
L 12
U 15
D 10
U 15
D 7
R 14
D 5
R 9
U 11
L 8
D 9
R 3
U 3
R 8
D 6
L 3
R 9
U 12
L 12
D 3
U 13
L 4
R 3
D 6
R 12
D 15
L 3
D 9
R 9
D 11
L 6
D 6
L 3
U 2
D 6
L 4
D 3
U 5
D 1
U 11
R 11
U 5
L 12
U 14
R 1
D 10
L 8
R 12
L 5
U 2
D 2
U 8
D 5
U 14
D 2
L 6
R 5
D 10
L 10
U 2
R 2
U 2
L 15
R 14
D 12
L 4
U 2
D 10
R 14
U 13
R 9
L 4
U 15
D 8
R 4
D 9
U 1
R 4
D 3
L 3
D 7
L 12
R 8
D 7
L 15
R 12
U 10
L 11
R 1
U 13
R 14
L 14
D 14
U 1
R 1
U 13
L 15
U 11
D 15
U 1
R 15
L 4
U 12
R 8
U 10
R 7
U 3
L 14
U 14
R 8
D 1
U 9
L 3
U 8
D 5
L 12
U 15
D 13
L 11
R 4
U 12
R 7
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