67 lines
1.5 KiB
Rust
67 lines
1.5 KiB
Rust
#![feature(test)]
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extern crate test;
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use std::collections::HashMap;
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type Parsed = Vec<usize>;
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fn read_input() -> String {
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String::from("15,12,0,14,3,1")
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}
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fn parse_input(raw: &str) -> Parsed {
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raw.split(',').filter_map(|x| x.parse().ok()).collect()
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}
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fn part1(parsed: &Parsed, limit: usize) -> usize {
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let mut iter = parsed.iter();
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let mut previous = HashMap::new();
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let mut current = 0;
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for i in 0..limit - 1 {
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if let Some(&n) = iter.next() {
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current = n;
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previous.insert(current, i);
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current = 0;
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continue;
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}
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println!("Adding {} to {:?}", current, previous);
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match previous.get(¤t) {
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Some(&position) => {
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previous.insert(current, i);
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current = i.saturating_sub(position);
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}
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None => {
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previous.insert(current, i);
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current = 0;
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}
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}
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}
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current
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}
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// only here so the test/bench macro works
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fn part2(parsed: &Parsed, limit: usize) -> usize {
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part1(parsed, limit)
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}
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fn main() {
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let input = parse_input(&read_input());
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println!("Part 1: {}", part1(&input, 2020));
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println!("Part 2: {}", part1(&input, 30000000));
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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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use aoc2020::*;
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use paste::paste;
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use test::black_box;
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const TEST_INPUT: &str = "0,3,6";
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test!(part1(2020) == 436);
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test!(part2(30000000) == 175594);
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//bench!(part1() == 0);
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//bench!(part2() == 0);
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bench_input!(len == 6);
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}
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