advent-of-code/aoc2015/src/day04.rs

49 lines
954 B
Rust
Raw Normal View History

2019-12-03 15:06:28 +01:00
use md5::{Digest, Md5};
use aoc::err;
use aoc::Result;
const INPUT: &str = include_str!("../input/day04.txt");
pub fn run() -> Result<()> {
println!("part 1: {}", part1(INPUT)?);
Ok(())
}
fn part1(input: &str) -> Result<u64> {
let input = input.trim_end();
let mut hasher = Md5::new();
for i in 0.. {
let content = format!("{}{}", input, i);
hasher.input(content);
let res = format!("{:x}", hasher.result_reset());
if &res[..5] == "00000" {
return Ok(i);
}
}
Err(err!("couldn't find a suitable number"))
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
#[ignore] // takes too long!
fn part1_provided() {
assert_eq!(part1("abcdef").unwrap(), 609043);
assert_eq!(part1("pqrstuv").unwrap(), 1048970);
}
#[test]
#[ignore] // takes too long!
fn part1_real() {
assert_eq!(part1(INPUT).unwrap(), 282749);
}
}