如何生成随机num :: BigUint？

Question

我需要一个随机的256位无符号数字。我发现RandBigInt该方法gen_biguint()具有特性，但是我很难找到实现它的方法。

我试过一段时间才这样做BigInt。此后，箱子已更新。这就是我用它来获得BigUint现在的方式。

extern crate num;
extern crate rand;

use num::bigint::{BigInt, BigUint, RandBigInt};

fn main() {
    let mut rng = rand::thread_rng();
    let mut n: BigUint = BigUint::default();
    loop {
        let bigUint: Option<BigUint> = rng.gen_bigint(256).to_biguint();
        match bigUint {
            Some(num) => {
                n = num.clone();
                println!("Found the 1st BigUint - {}", num);
                break;
            }
            _ => {}
        }
    }
}

我的Cargo.toml中的内容

extern crate num;
extern crate rand;

use num::bigint::{BigInt, BigUint, RandBigInt};

fn main() {
    let mut rng = rand::thread_rng();
    let mut n: BigUint = BigUint::default();
    loop {
        let bigUint: Option<BigUint> = rng.gen_bigint(256).to_biguint();
        match bigUint {
            Some(num) => {
                n = num.clone();
                println!("Found the 1st BigUint - {}", num);
                break;
            }
            _ => {}
        }
    }
}

我确信必须有一些简单的方法来实现这一目标。

Answer 1

从的自述文件num：

该rand功能允许在随机的特征num-bigint和num-complex。

[dependencies]
num-bigint = { version = "0.2.0", features = ["rand"] }
rand = "0.5.4"

然后，您需要使用RandomBits实现的rand::Distribution：

extern crate num_bigint;
extern crate rand;

use num_bigint::{BigInt, BigUint, RandomBits};
use rand::Rng;

fn main() {
    let mut rng = rand::thread_rng();

    let signed: BigInt = rng.sample(RandomBits::new(256));
    let unsigned: BigUint = rng.sample(RandomBits::new(256));

    println!("{}, {}", signed, unsigned)
}