如何从反向加权列表中随机选择？(How can I make a random selection from an inversely-weighted list?)

 给定一个整数列表，例如1, 2, 3, 4 ，我知道如何根据它们的重量选择项目。 示例项目的概率分别为10％，20％，30％和40％。 
 
 是否有一种同样简单的方法来选择基于其重量的倒数的项目？ 使用此方法，示例列表将等于1, 1/2, 1/3, 1/4 （48％，24％，16％，12％）的加权列表，但我想避免转换和使用浮点运算。 （假设所有整数都是正数且非零。） 

Given a list of integers, e.g. 1, 2, 3, 4, I know how to select items based on their weight. The example items would have probabilities of 10%, 20%, 30%, and 40%, respectively.
 
Is there an equally simple method of selecting items based on the inverse of their weight? With this method, the example list would be equal to a weighted list of 1, 1/2, 1/3, 1/4 (48%, 24%, 16%, 12%), but I want to avoid the conversion and use of floating-point arithmetic. (Assume all of the integers are positive and non-zero.)

原文：https://stackoverflow.com/questions/7762569