Number System

Complex numbers

use std::f64::consts::PI;
use num::complex::Complex;

fn main() {
    let complex_integer = num::complex::Complex::new(10, 20);
    let complex_float = num::complex::Complex::new(10.1, 20.1);

    println!("Complex integer: {}", complex_integer);
    println!("Complex float: {}", complex_float);

    let complex_num1 = num::complex::Complex::new(10.0, 20.0);
    let complex_num2 = num::complex::Complex::new(3.1, -4.2);

    let sum = complex_num1 + complex_num2;  // must be of same type

    println!("Sum: {}", sum);

    let x = Complex::new(0.0, 2.0*PI);
    println!("e^(2i * pi) = {}", x.exp());
}

Big Integers

BigInts are used for calculations exceeding 128 bits.

use num::bigint::{BigInt, ToBigInt};

fn factorial(x: i32) -> BigInt {
    if let Some(mut factorial) = 1.to_bigint() {
        for i in 1..=x {
            factorial = factorial * i;
        }
        factorial
    }
    else {
        panic!("Failed to calculate factorial!");
    }
}

fn main() {
    println!("{}! equals {}", 100, factorial(100));
}