考慮以下代表經紀人的類：public class Broker{ public string Name = string.Empty; public int Weight = 0; public Broker(string n, int w) { this.Name = n; this.Weight = w; }}考慮到它們的權重，我想從一個數組中隨機選擇一個Broker。您如何看待下面的代碼？class Program { private static Random _rnd = new Random(); public static Broker GetBroker(List<Broker> brokers, int totalWeight) { // totalWeight is the sum of all brokers' weight int randomNumber = _rnd.Next(0, totalWeight); Broker selectedBroker = null; foreach (Broker broker in brokers) { if (randomNumber <= broker.Weight) { selectedBroker = broker; break; } randomNumber = randomNumber - broker.Weight; } return selectedBroker; } static void Main(string[] args) { List<Broker> brokers = new List<Broker>(); brokers.Add(new Broker("A", 10)); brokers.Add(new Broker("B", 20)); brokers.Add(new Broker("C", 20)); brokers.Add(new Broker("D", 10)); // total the weigth int totalWeight = 0; foreach (Broker broker in brokers) { totalWeight += broker.Weight; } while (true) { Dictionary<string, int> result = new Dictionary<string, int>(); Broker selectedBroker = null; for (int i = 0; i < 1000; i++) { selectedBroker = GetBroker(brokers, totalWeight); if (selectedBroker != null) { if (result.ContainsKey(selectedBroker.Name)) { result[selectedBroker.Name] = result[selectedBroker.Name] + 1; }我不太自信 當我運行此代碼時，經紀人A總是比經紀人D獲得更多的匹配，而且它們的權重相同。有沒有更準確的算法？
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慕姐4208626
TA貢獻1852條經驗 獲得超7個贊
class Program
{
static void Main(string[] args)
{
var books = new List<Book> {
new Book{Isbn=1,Name="A",Weight=1},
new Book{Isbn=2,Name="B",Weight=100},
new Book{Isbn=3,Name="C",Weight=1000},
new Book{Isbn=4,Name="D",Weight=10000},
new Book{Isbn=5,Name="E",Weight=100000}};
Book randomlySelectedBook = WeightedRandomization.Choose(books);
}
}
public static class WeightedRandomization
{
public static T Choose<T>(List<T> list) where T : IWeighted
{
if (list.Count == 0)
{
return default(T);
}
int totalweight = list.Sum(c => c.Weight);
Random rand = new Random();
int choice = rand.Next(totalweight);
int sum = 0;
foreach (var obj in list)
{
for (int i = sum; i < obj.Weight + sum; i++)
{
if (i >= choice)
{
return obj;
}
}
sum += obj.Weight;
}
return list.First();
}
}
public interface IWeighted
{
int Weight { get; set; }
}
public class Book : IWeighted
{
public int Isbn { get; set; }
public string Name { get; set; }
public int Weight { get; set; }
}
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