public static PairPoint brutforce(int N, List <Point> points)
{
PairPoint pp = new PairPoint();
double distance = Double.MaxValue;
for (int i = 0; i < N; i++)
{
for (int j = 0; j < N; j++)
{
if (i == j)
{
continue;
}
PairPoint temp = new PairPoint();
temp.Point1 = points[i];
temp.Point2 = points[j];
if (temp.Distance() < distance)
{
distance = temp.Distance();
pp = temp;
}
//double currDistance = Math.Sqrt(Math.Pow(points[i].X - points[j].X, 2) + Math.Pow(points[i].Y - points[j].Y, 2));
//if(currDistance<distance)
//{
// distance = currDistance;
// pp.Point1 = points[i];
// pp.Point2 = points[j];
//}
}
}
return(pp);
}
private PairPoint MyClosestRec(List <Point> sortedByX)
{
int count = sortedByX.Count;
if (count <= 4)
{
return(Program.brutforce(count, sortedByX));
}
var leftByX = sortedByX.Take(count / 2).ToList();
var leftResult = MyClosestRec(leftByX);
var rightByX = sortedByX.Skip(count / 2).ToList();
var rightResult = MyClosestRec(rightByX);
var result = rightResult.Distance() < leftResult.Distance() ? rightResult : leftResult;
var midX = leftByX.Last().X;
var bandWidth = result.Distance();
var inBandByX = sortedByX.Where(p => Math.Abs(midX - p.X) <= bandWidth);
var inBandByY = inBandByX.OrderBy(p => p.Y).ToArray();
int last = inBandByY.Length - 1;
for (int i = 0; i < last; i++)
{
var point1 = inBandByY[i];
for (int j = i + 1; j <= last; j++)
{
var point2 = inBandByY[j];
if ((point1.Y - point2.Y) >= result.Distance())
{
break;
}
PairPoint temp = new PairPoint();
temp.Point1 = point1;
temp.Point2 = point2;
if (temp.Distance() < result.Distance())
{
result = temp;
}
}
}
return(result);
}
static void Main(string[] args)
{
int[] iters = { 5, 10, 20, 30, 100, 1000 };
List <Point> pointsst = init(1000);
PairPoint ppst = brutforce(1000, pointsst);
Console.WriteLine("Алгоритм грубой силы");
Console.WriteLine("Время работы алгоритма");
Console.WriteLine("Первая точка");
Console.WriteLine("(" + ppst.Point1.X + "," + ppst.Point1.Y + ")");
Console.WriteLine("Вторая точка");
Console.WriteLine("(" + ppst.Point2.X + "," + ppst.Point2.Y + ")");
Console.WriteLine("Расстояние между точками");
Console.WriteLine(ppst.Distance());
Console.ReadLine();
DivideAndConquer dacst = new DivideAndConquer(1000, pointsst);
PairPoint pp1st = dacst.MyClosestDivide();
Console.WriteLine("Алгоритм декомпозиции");
Console.WriteLine("Время работы алгоритма");
Console.WriteLine("Первая точка");
Console.WriteLine("(" + pp1st.Point1.X + "," + pp1st.Point1.Y + ")");
Console.WriteLine("Вторая точка");
Console.WriteLine("(" + pp1st.Point2.X + "," + pp1st.Point2.Y + ")");
Console.WriteLine("Расстояние между точками");
Console.WriteLine(pp1st.Distance());
Console.ReadLine();
foreach (int i in iters)
{
for (int j = 0; j < 100; j++)
{
//List<Point> points = new List<Point>();
//Point point1 = new Point();
//point1.X = 3;
//point1.Y = 1;
//points.Add(point1);
//Point point2 = new Point();
//point2.X = 4;
//point2.Y = 2;
//points.Add(point2);
//Point point3 = new Point();
//point3.X = 5;
//point3.Y = 6;
//points.Add(point3);
//Point point4 = new Point();
//point4.X = 7;
//point4.Y = 8;
//points.Add(point4);
//Point point5 = new Point();
//point5.X = 6;
//point5.Y = 4;
//points.Add(point5);
List <Point> points = init(i);
Stopwatch timer = new Stopwatch();
timer.Start();
PairPoint pp = brutforce(i, points);
timer.Stop();
Console.WriteLine("Алгоритм грубой силы");
long time = timer.ElapsedMilliseconds;
Console.WriteLine("Время работы алгоритма");
Console.WriteLine(time);
Console.WriteLine("Первая точка");
Console.WriteLine("(" + pp.Point1.X + "," + pp.Point1.Y + ")");
Console.WriteLine("Вторая точка");
Console.WriteLine("(" + pp.Point2.X + "," + pp.Point2.Y + ")");
Console.WriteLine("Расстояние между точками");
Console.WriteLine(pp.Distance());
DivideAndConquer dac = new DivideAndConquer(i, points);
timer.Reset();
timer.Start();
PairPoint pp1 = dac.MyClosestDivide();
timer.Stop();
long time2 = timer.ElapsedMilliseconds;
Console.WriteLine("Алгоритм декомпозиции");
Console.WriteLine("Время работы алгоритма");
Console.WriteLine(time2);
Console.WriteLine("Первая точка");
Console.WriteLine("(" + pp1.Point1.X + "," + pp1.Point1.Y + ")");
Console.WriteLine("Вторая точка");
Console.WriteLine("(" + pp1.Point2.X + "," + pp1.Point2.Y + ")");
Console.WriteLine("Расстояние между точками");
Console.WriteLine(pp1.Distance());
}
Console.ReadLine();
}
}
