public void ReturnsEmptySetIfNothingFound()
{
var bfs = new BreadthFirstSearch <int>(EqualityComparer <int> .Default, _ => Enumerable.Empty <int>());
var result = bfs.FindAll(0, x => x < 0);
Assert.AreEqual(0, result.Count);
}
public void ParallelSearchIsExhaustive()
{
var expansionCount = 0;
IEnumerable <Point> Expander(Point p)
{
_ = Interlocked.Increment(ref expansionCount);
if (p.X + p.Y >= 100)
{
yield break;
}
yield return(p + new Size(1, 0));
yield return(p + new Size(0, 1));
}
var bfs = new BreadthFirstSearch <Point>(EqualityComparer <Point> .Default, Expander)
{
PerformParallelSearch = true
};
var result = bfs.FindAll(Point.Empty, p => (p.X + p.Y) % 5 == 0);
var resultCount = (100 / 5 * (100 + 5) / 2) + (100 / 5) + 1;
Assert.AreEqual(resultCount, result.Count);
Assert.AreEqual(5151, expansionCount);
}
public void FindsInitialNode()
{
var bfs = new BreadthFirstSearch <int>(EqualityComparer <int> .Default, _ => Enumerable.Empty <int>());
var result = bfs.FindAll(33, x => x > 0);
Assert.AreEqual(1, result.Count);
Assert.AreEqual(0, result[0].Length);
Assert.AreEqual(1, result[0].Steps.Length);
Assert.AreEqual(33, result[0].Steps[0]);
}
static void Main(string[] args)
{
var input = File.ReadAllLines("../../../input.txt");
var sw = new Stopwatch();
sw.Start();
var wires = input.Select(WireToPoints).ToList();
var crossings = new HashSet <Point>(wires[0].Keys.Intersect(wires[1].Keys));
var closest = crossings.MinBy(DistanceFromOrigin).First();
Console.WriteLine($"Part 1: point {closest} is in both wires and close to the origin.");
var shortest = crossings.MinBy(x => wires[0][x] + wires[1][x]).First();
var delay = wires[0][shortest] + wires[1][shortest];
Console.WriteLine($"Part 2: point {shortest} has signal delay {delay}");
var search1 = new BreadthFirstSearch <Point>(EqualityComparer <Point> .Default, p =>
_mapDirectionToSize.Values.Select(s => p + s).Where(wires[0].Keys.Contains)
)
{
PerformParallelSearch = false
};
var wire1 = search1.FindAll(Point.Empty, p => crossings.Contains(p))
.ToDictionary(x => x.Target, x => x.Length);
var search2 = new BreadthFirstSearch <Point>(EqualityComparer <Point> .Default, p =>
_mapDirectionToSize.Values.Select(s => p + s).Where(wires[1].Keys.Contains)
)
{
PerformParallelSearch = false
};
var wire2 = search2.FindAll(Point.Empty, p => crossings.Contains(p))
.ToDictionary(x => x.Target, x => x.Length);
var shortedCrossings = crossings.MinBy(x => wire1[x] + wire2[x]).First();
delay = wire1[shortedCrossings] + wire2[shortedCrossings];
Console.WriteLine($"Part 3: point {shortedCrossings} has signal delay {delay}");
sw.Stop();
Console.WriteLine($"Solving took {sw.ElapsedMilliseconds}ms.");
_ = Console.ReadLine();
}
public void FindTargetSetInInfiniteGraph()
{
var bfs = new BreadthFirstSearch <int>(EqualityComparer <int> .Default, x => new[] { x * 2, x * 3 });
var result = bfs.FindAll(1, x => x < 30, null, 12);
var expected = new[] { 1, 2, 4, 8, 16, 3, 6, 12, 24, 9, 18, 27 };
Assert.AreEqual(12, result.Count);
foreach (var target in expected)
{
Assert.IsTrue(result.Any(p => p.Target == target));
}
}
public void FindAllTargetsInFiniteGraph()
{
var bfs = new BreadthFirstSearch <int>(
EqualityComparer <int> .Default,
(int x) => (x > 100) ? Enumerable.Empty <int>() : new[] { x * 2, x * 3 });
var result = bfs.FindAll(1, x => x < 30);
var expected = new[] { 1, 2, 4, 8, 16, 3, 6, 12, 24, 9, 18, 27 };
Assert.AreEqual(12, result.Count);
foreach (var target in expected)
{
Assert.IsTrue(result.Any(p => p.Target == target));
}
}
static void Main()
{
var input = File.ReadAllLines("../../../input.txt");
var sw = new Stopwatch();
sw.Start();
//var items = input.Select(s => s.Split(')'));
//var orbitedby = items.ToLookup(x => x[0], x => x[1]);
//var orbits = items.ToDictionary(x => x[1], x => x[0]);
//var search = new BreadthFirstSearch<string>(
// EqualityComparer<string>.Default,
// node => orbitedby[node].Concat(orbits.GetOrEmpty(node)))
//{ PerformParallelSearch = false };
//var depths = search.FindAll("COM", x => true);
//var sum = depths.Sum(path => path.Length);
//Console.WriteLine($"Part 1: The total number of orbits is {sum}.");
//var path = search.FindFirst("SAN", x => x == "YOU");
//Console.WriteLine($"Part 2: The route von Santa to you has {path.Length - 2} transfers.");
var graph = Graph.FromEdges(input, s => s.Split(')').ToTuple2());
var search = new BreadthFirstSearch <GraphNode <string, string> >(
graph.NodeComparer,
node => node.Neighbors)
{
PerformParallelSearch = false
};
var depths = search.FindAll(graph.Nodes["COM"], x => true);
var sum = depths.Sum(path => path.Length);
Console.WriteLine($"Part 1: The total number of orbits is {sum}.");
var path = search.FindFirst(graph.Nodes["SAN"], x => x.Value == "YOU");
Console.WriteLine($"Part 2: The route von Santa to you has {path.Length - 2} transfers.");
sw.Stop();
Console.WriteLine($"Solving took {sw.ElapsedMilliseconds}ms.");
_ = Console.ReadLine();
}
private static void Main(string[] args)
{
var inputText = File.ReadAllLines(@"../../../input.txt");
field = inputText.Select(x => x.ToCharArray()).ToArray();
rows = field.Length;
columns = field[0].Length;
var allNumbers = field.SelectMany(x => x).Where(char.IsDigit).ToArray();
var numberPositions = new Dictionary <char, Coordinate>();
for (var rowIndex = 0; rowIndex < rows; rowIndex++)
{
for (var colIndex = 0; colIndex < columns; colIndex++)
{
var c = new Coordinate(colIndex, rowIndex);
var content = ContentAt(c);
if (char.IsDigit(content))
{
numberPositions.Add(content, c);
}
}
}
foreach (var position in numberPositions)
{
Console.WriteLine($"Number {position.Key} found at {position.Value}");
}
var bfs = new BreadthFirstSearch <Coordinate, MoveDirection>(new CoordinateIdentical(), GetPossibleMovements,
GetPosition);
var distances = new Dictionary <string, int>();
foreach (var number in numberPositions.Keys)
{
var others = bfs.FindAll(numberPositions[number], coords => ContentAt(coords) > number);
foreach (var other in others)
{
var edge1 = string.Concat(number, ContentAt(other.Target));
var edge2 = string.Concat(ContentAt(other.Target), number);
var edgeLength = other.Length - 1;
distances.Add(edge1, edgeLength);
distances.Add(edge2, edgeLength);
Console.WriteLine($"Edge {edge1} / {edge2} is {edgeLength} long.");
}
}
var allTrips = new Permutations <char>(allNumbers);
var allTripsWithLengths = new Dictionary <string, int>();
foreach (IList <char> trip in allTrips)
{
if (trip[0] != '0')
{
continue;
}
trip.Add('0');
var name = string.Concat(trip);
var length = 0;
foreach (var walk in trip.PairwiseWithOverlap())
{
var edge = string.Concat(walk.Item1, walk.Item2);
length += distances[edge];
}
allTripsWithLengths.Add(name, length);
}
Console.WriteLine();
var min = allTripsWithLengths.OrderBy(x => x.Value).Take(3);
foreach (var trip in min)
{
Console.WriteLine($"Trip {trip.Key} is {trip.Value} long");
}
Console.ReadLine();
}