public bool Equals(TwoDPoint p)
{
// If parameter is null return false:
if ((object)p == null)
{
return(false);
}
// Return true if the fields match:
return((x == p.x) && (y == p.y));
}
public static void Main(string[] args)
{
List <TwoDPoint> points = new List <TwoDPoint>(100000);
int[] hashOfPoints = new int[points.Capacity];
Random rn = new Random();
for (int i = 0; i < points.Capacity; i++)
{
TwoDPoint point = new TwoDPoint(0, 0);
do
{
point.x = rn.Next(-100000, 100000);
point.y = rn.Next(-100000, 100000);
}while (points.Contains(point));
points.Add(point);
hashOfPoints[i] = point.GetHashCode();
}
for (int i = 0; i < hashOfPoints.Length - 1; i++)
{
for (int j = i + 1; j < hashOfPoints.Length; j++)
{
if (hashOfPoints[i] == hashOfPoints[j])
{
for (int k = j + 1; k < hashOfPoints.Length; k++)
{
hashOfPoints[k - 1] = hashOfPoints[k];
}
Array.Resize(ref hashOfPoints, hashOfPoints.Length - 1);
j--;
}
}
}
TwoDPoint point1 = new TwoDPoint(10, 10);
TwoDPoint point2 = new TwoDPoint(10, 10);
if (point1.GetHashCode() == point2.GetHashCode())
{
Console.WriteLine("У одинаковых точек хеш совпадает");
}
else
{
Console.WriteLine("!!!У одинаковых точек хеш не совпадает");
}
double accuracy = 100 * Convert.ToDouble(hashOfPoints.Length) / Convert.ToDouble(points.Capacity);
Console.WriteLine($"Уникальность хеш-функции {accuracy}%");
}
public static void Demo(string[] args)
{
TwoDPoint point1 = new TwoDPoint(1, 10);
TwoDPoint point2 = new TwoDPoint(1, 10);
object object1 = (object)point1;
object object2 = (object)point2;
Console.WriteLine(point1.Equals(point2));
Console.WriteLine(point1 == point2);
Console.WriteLine(object1.Equals(object2));
Console.WriteLine(object1 == object2); // false !!!! почему?
// в чем разница определений методов Equals и == ?
}
public override bool Equals(Object obj)
{
if (obj == null)
{
return(false);
}
TwoDPoint p = obj as TwoDPoint;
if ((Object)p == null)
{
return(false);
}
// Return true if the fields match:
return((x == p.x) && (y == p.y));
}
public override bool Equals(Object obj)
{
// If parameter is null return false.
if (obj == null)
{
return(false);
}
// If parameter cannot be cast to Point return false.
TwoDPoint p = obj as TwoDPoint;
if ((Object)p == null)
{
return(false);
}
// Return true if the fields match:
return((x == p.x) && (y == p.y));
}
public static void Demo(string[] args)
{
TwoDPoint point1 = new TwoDPoint(1, 10);
TwoDPoint point2 = new TwoDPoint(1, 10);
Console.WriteLine("Hash for point1: {0}\tHash for point2: {1}", point1.GetHashCode(), point2.GetHashCode());
TwoDPointWithHash newPoint1 = new TwoDPointWithHash(1, 10);
TwoDPointWithHash newPoint2 = new TwoDPointWithHash(1, 10);
Console.WriteLine("Hash for point1: {0}\tHash for point2: {1}", newPoint1.GetHashCode(), newPoint2.GetHashCode());
// уникальных точек будет 2, хотя координаты их одинаковы
Console.WriteLine("TwoDPointWithHash:");
var twoDPointList = new List <TwoDPoint> {
point1, point2
};
var distinctTwoDPointList = twoDPointList.Distinct();
foreach (var point in distinctTwoDPointList)
{
Console.WriteLine("Distinct point: {0}", point);
}
// одна уникальная точка
Console.WriteLine("TwoDPointWithHash:");
var twoDPointWithHashList = new List <TwoDPointWithHash> {
newPoint1, newPoint2
};
var distinctTwoDPointWithHashList = twoDPointWithHashList.Distinct();
foreach (var point in distinctTwoDPointWithHashList)
{
Console.WriteLine("Distinct point: {0}", point);
}
}
