class P { public int XX, YY, VX, VY; } List

input; void Main() { input = File .ReadAllLines(Path.Combine(Path.GetDirectoryName(Util.CurrentQueryPath), @"10_input.txt")) .Where(p => !string.IsNullOrWhiteSpace(p)) .Select(l => new P { XX=int.Parse(l.Substring(10,6).Trim()), YY=int.Parse(l.Substring(18,6).Trim()), VX=int.Parse(l.Substring(36,2).Trim()), VY=int.Parse(l.Substring(40,2).Trim()), }) .ToList(); for (;;) { foreach (var v in input) { v.XX += v.VX; v.YY += v.VY; } if (input.Any(Alone)) continue; Print(); return; } } bool Alone(P p) => !input.Any(i => i != p && Math.Abs(i.XX-p.XX)<=1 && Math.Abs(i.YY-p.YY)<=1); void Print() { int minX = input.Min(i => i.XX); int maxX = input.Max(i => i.XX); int minY = input.Min(i => i.YY); int maxY = input.Max(i => i.YY); var b = new StringBuilder(); for (int y = minY; y <= maxY; y++) { for (int x = minX; x <= maxX; x++) { b.Append(input.Any(i => i.XX==x&&i.YY==y)?'#':'.'); } b.AppendLine(); } b.ToString().Dump(); }