如何编码获得p次1和（1-p）次0？ [英] How do I code to get p times 1 and (1-p) times 0?

问题描述

使用C ++随机数生成器rand（），实现一个偏差硬币，输出1概率为p，0概率为1-p。不要在你将要实现的功能中播种随机数生成器！



我尝试过：



我试过这个来生成0和1：



float output = rand（）％2;

Using the C++ random number generator rand(), implement a biased coin that outputs 1 with probability p and 0 with probability 1–p. Do not seed the random number generator within the function you will be implementing!

What I have tried:

I have tried this to generate 0 and 1:

float output=rand()%2;

推荐答案

仔细阅读问题：它需要您生成一个偏置硬币：一个返回0比1更多的硬币，反之亦然，取决于 p <给出的概率/ code>



因此，您需要使用的值，而不是使用2直接50:50 p 偏向你的结果。由于 p 是0到1之间的浮点值，而 rand 总是返回一个整数，你将不得不偷偷摸摸。

我首先做两个测试：p = 0（在这种情况下返回0）和p = 1（在这种情况下返回1）。如果它们都失败了，那么生成一个随机数并将其乘以p。如果结果大于最大值的一半 rand 可以在系统中返回，则返回1，否则返回0.



但这是你的作业，不是我的作业 - 所以我不会给你任何代码！

Read the question carefully: it requires you to produce a BIASED coin: one that returns more 0's than 1's or vice versa, dependent on the probability given in p

So, instead of using 2 which gives you a straight 50:50, you need to use the value of p to bias your results. Since p is a floating point value between 0 and 1 and rand always returns an integer, you are going to have to get sneaky.
I'd start by doing two tests: p = 0 (in which case return 0) and p = 1 (in which case return 1). If they both fail, then generate a random number and multiply it by p. If the result is greater than half the maximum value rand can return in your system then return a 1, otherwise return a 0.

But this is your homework, not mine - so I'll give you no code!

1）选择你的语言。

2）研究兰德是如何用这种语言工作的。

1) Choose your language.
2) study how rand is working in that language.

引用：

实现一个有概率为p的输出1的偏置硬币0概率为1-p。

implement a biased coin that outputs 1 with probability p and 0 with probability 1–p.

这个重要的词是有偏见的。这意味着两步绘图。

假设赔率为0.33和0.67。

- 抽取一个随机数

- 随机查看赔率并决定结果。



我们不做你的家庭作业。

所以只是提示一些。

the important word is 'biased'. This imply a 2 step drawing.
Say the odds are 0.33 and 0.67.
- draw a random number
- check the random against odds and decide of the result.

We do not do your HomeWork.
So just a few hints.

这篇关于如何编码获得p次1和（1-p）次0？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！