2021-12-01 07:30:10 +01:00
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use std::fmt::Write;
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use anyhow::Result;
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const INPUT: &str = include_str!("../input/day01.txt");
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pub fn run() -> Result<String> {
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let mut res = String::with_capacity(128);
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writeln!(res, "part 1: {}", part1(INPUT)?)?;
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writeln!(res, "part 2: {}", part2(INPUT)?)?;
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Ok(res)
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}
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fn part1(input: &str) -> Result<usize> {
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let measurements = input
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.lines()
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.map(|line| line.parse::<u64>().map_err(anyhow::Error::new))
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.collect::<Result<Vec<_>>>()?;
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2021-12-01 10:57:51 +01:00
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Ok(count_increases(measurements.iter()))
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}
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fn count_increases<I, C>(numbers: I) -> usize
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where
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C: std::cmp::PartialOrd,
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I: Iterator<Item = C> + Clone,
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{
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numbers
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.clone()
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.zip(numbers.skip(1))
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.filter(|(a, b)| a < b)
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.count()
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2021-12-01 07:30:10 +01:00
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}
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fn part2(input: &str) -> Result<usize> {
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let measurements = input
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.lines()
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.map(|line| line.parse::<u64>().map_err(anyhow::Error::new))
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.collect::<Result<Vec<_>>>()?;
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2021-12-01 10:57:51 +01:00
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Ok(count_increases(
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measurements.windows(3).map(|w| w.iter().sum::<u64>()),
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))
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2021-12-01 07:30:10 +01:00
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}
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2021-12-01 07:34:50 +01:00
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#[cfg(test)]
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mod tests {
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use super::*;
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const PROVIDED: &str = include_str!("../input/day01_provided.txt");
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#[test]
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fn part1_provided() {
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assert_eq!(part1(PROVIDED).unwrap(), 7);
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}
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#[test]
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fn part1_real() {
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assert_eq!(part1(INPUT).unwrap(), 1502);
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}
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#[test]
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fn part2_provided() {
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assert_eq!(part2(PROVIDED).unwrap(), 5);
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}
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#[test]
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fn part2_real() {
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assert_eq!(part2(INPUT).unwrap(), 1538);
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}
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}
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