AOC2021 Day13

import 'dart:io';
import 'dart:math';
import 'package:more/more.dart';
import 'package:collection/collection.dart';

parseLine(String l) => l.split('-').toList();
late Set<Point> grid;
late List<String> folds;

Point pnt(Iterable l) => Point(l.first, l.last);
parseLines(List<String> lines) {
  var ls = lines.splitBefore((e) => e.isEmpty).toList();
  grid = {for (var e in ls.first) pnt(e.split(',').map(int.parse))};
  folds = [for (var l in ls.last.skip(1)) l.substring(11)];
}

applyFolds(List<String> folds) {
  for (var f in folds) {
    int l = int.parse(f.substring(2));
    grid = <Point>{
      for (var k in grid)
        Point(f.startsWith('x') && k.x > l ? l - (k.x - l) : k.x,
            f.startsWith('y') && k.y > l ? l - (k.y - l) : k.y)
    };
  }
}

main() {
  var lines = File('data/data13_01.txt').readAsLinesSync();
  var t = DateTime.now();
  parseLines(lines);
  applyFolds(folds);
  print('${DateTime.now().difference(t).inMilliseconds} milliseconds');
  var h = grid.map((k) => k.y).max.toInt() + 1;
  var w = grid.map((k) => k.x).max.toInt() + 1;
  for (var r in 0.to(h)) {
    print([for (var c in 0.to(w)) grid.contains(Point(c, r)) ? '█' : ' ']
        .join(''));
  }
}