25 stable releases (6 major)
7.0.0 | Jan 4, 2024 |
---|---|
6.0.3 | Jan 4, 2024 |
5.0.1 | Jan 2, 2024 |
4.0.1 | Jan 1, 2024 |
1.0.5 | Dec 25, 2023 |
#444 in Algorithms
22 downloads per month
135KB
2.5K
SLoC
Big Int
Simple library for arbitrary-precision, arbitrary-base arithmetic, supporting arbitrarily large integers of any base from 2 to u64::MAX
.
use big_int::prelude::*;
let mut a: Loose<10> = "9000000000000000000000000000000000000000".parse().unwrap();
a /= 13.into();
assert_eq!(a, "692307692307692307692307692307692307692".parse().unwrap());
let mut b: Loose<16> = a.convert();
assert_eq!(b, "208D59C8D8669EDC306F76344EC4EC4EC".parse().unwrap());
b >>= 16.into();
let c: Loose<2> = b.convert();
assert_eq!(c, "100000100011010101100111001000110110000110011010011110110111000011".parse().unwrap());
let mut d: Tight<256> = c.convert();
d += vec![15, 90, 0].into();
assert_eq!(d, vec![2, 8, 213, 156, 141, 134, 121, 71, 195].into());
let e: Tight<10> = d.convert();
assert_eq!(format!("{e}"), "37530075201422313411".to_string());
This crate contains five primary big int implementations:
LooseBytes<BASE>
- A collection of loosely packed 8-bit byte values representing each digit. Slightly memory inefficient, but with minimal performance overhead. Capable of representing any base from 2-256.LooseShorts<BASE>
- A collection of loosely packed 16-bit short values representing each digit. Somewhat memory inefficient, but with minimal performance overhead. Capable of representing any base from 2-65536.LooseWords<BASE>
- A collection of loosely packed 32-bit word values representing each digit. Fairly memory inefficient, but with minimal performance overhead. Capable of representing any base from 2-2^32.Loose<BASE>
- A collection of loosely packed 64-bit ints representing each digit. Very memory inefficient, but with minimal performance overhead. Capable of representing any base from 2-2^64.Tight<BASE>
- A collection of tightly packed bits representing each digit. Maximally memory efficient, and capable of representing any base from 2-2^64. However, the additional indirection adds some performance overhead.
Ints support most basic arithmetic operations, including addition, subtraction, multiplication,
division, exponentiation, logarithm, nth root, and left/right shifting. Notably, shifting acts on the BASE
of the associated number, increasing or decreasing the magnitude by powers of BASE
as opposed to powers of 2.
Dependencies
~300–760KB
~18K SLoC