随机化值而不超过值？

Question

我有一些时间思考以下内容,我想制作一个按钮来随机化一些技能的全部价值.问题是我有10分可以分配4种技能,想法是选择不超过10分的随机数.

我曾想过这个

public int startPts = 10, usedPts = 0;
public int skill1 = 0, skill2 = 0, skill3 = 0, skill4 = 0;

public void ButtonRandom(){
   startPts = 10;
   usedPts = 0;

   skill1 = Random.Range( 1, 10 );
   usedPts += skill1;

   skill2 = Random.Range( 1, usedPts );
   usedPts += skill2;

   skill3 = Random.Range( 1, usedPts );
   usedPts += skill3;

   skill4 = startPts - usedPts;
   usedPts += skill4;

   startPts = startPts - usedPts;

 }

我也尝试了几种条件和重复方法,但我没有得到理想的结果.因为有时它超过了10个点,所以当我放置条件时,不使用或仅更改前2个值时离开点.

感谢你们.

Answer 1

如果您想要的是每个可能的分布同样可能,那么到目前为止所提供的解决方案都不起作用.到目前为止提出的解决方案选择3, 3, 2, 2的频率要高得多7, 1, 1, 1.你明白为什么吗？

如果您所需的分布在可能性上是均匀的,则此算法为您提供:

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    // Partition n into m summands
    static IEnumerable<IEnumerable<int>> Partitions(int n, int m)
    {
      // There is no partition of n into zero summands for any value of n other than zero.
      // Otherwise, give the partitions that begin with 0, 1, 2, ... n.
      if (m == 0) 
      {
        if (n == 0)
          yield return Enumerable.Empty<int>();
      }
      else 
      {
        for (int nn = 0; nn <= n; ++nn)
            foreach(var p in Partitions(n - nn, m - 1))
                yield return (new[] { nn }).Concat(p);
      }
    }

    public static void Main()
    {
        // Divide up six points into four buckets:
        var partitions = Partitions(6, 4).ToArray();
        // Now choose a random member of partitions, and 
        // add one to each element of that sequence. Now
        // you have ten points total, and every possibility is 
        // equally likely.

        // Let's visualize the partitions:
        foreach(var p in partitions)
            Console.WriteLine(string.Join(",", p));

    }
}