50 lines
1.2 KiB
Rust
50 lines
1.2 KiB
Rust
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use color_eyre::{eyre::eyre, Result};
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pub fn solve() -> Result<()> {
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let input_data = include_str!("../../data/day_07.txt").trim();
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println!("Day 07 Part 1: {}", part_1(input_data)?);
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println!("Day 07 Part 2: {}", part_2(input_data)?);
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Ok(())
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}
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fn parse_crabs(input: &str) -> Result<(Vec<isize>, isize)> {
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let crabs = input
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.split(",")
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.map(str::parse)
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.collect::<Result<Vec<_>, _>>()?;
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let highest_crab = *crabs
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.iter()
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.max()
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.ok_or(eyre!("Unable to find highest crab"))?;
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Ok((crabs, highest_crab))
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}
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fn part_1(input: &str) -> Result<isize> {
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let (crabs, highest_crab) = parse_crabs(input)?;
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(0..=highest_crab)
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.map(|target_position| {
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crabs
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.iter()
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.map(|crab| (target_position - crab).abs())
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.sum()
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})
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.min()
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.ok_or(eyre!("Unable to find lowest fuel"))
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}
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fn part_2(input: &str) -> Result<isize> {
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let (crabs, highest_crab) = parse_crabs(input)?;
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(0..=highest_crab)
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.map(|target_position| {
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crabs
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.iter()
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.map(|crab| (target_position - crab).abs())
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.map(|steps| (steps * (steps + 1)) / 2)
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.sum()
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})
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.min()
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.ok_or(eyre!("Unable to find lowest fuel"))
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}
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