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