89 lines
1.9 KiB
Rust
89 lines
1.9 KiB
Rust
use aoc_2022::file_to_lines;
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use tracing::*;
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use tracing_subscriber::EnvFilter;
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use std::cmp::max;
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struct Accum {
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max_sum: i32,
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current_sum: i32,
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}
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impl Accum {
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fn new() -> Accum {
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Accum {
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max_sum: 0,
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current_sum: 0,
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}
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}
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}
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fn part_1(input: &[i32]) -> i32 {
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input
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.iter()
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.fold(Accum::new(), |a, &x| {
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if x == -1 {
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Accum {
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max_sum: max(a.max_sum, a.current_sum),
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current_sum: 0,
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}
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} else {
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Accum {
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max_sum: a.max_sum,
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current_sum: a.current_sum + x,
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}
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}
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})
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.max_sum
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}
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fn part_2(input: &[i32]) -> i32 {
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let mut calories: Vec<i32> = Vec::new();
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let last_elf = input
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.iter()
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.fold(Accum::new(), |a, &x| {
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if x == -1 {
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calories.push(a.current_sum);
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Accum::new()
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} else {
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Accum {
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max_sum: a.max_sum,
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current_sum: a.current_sum + x,
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}
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}
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})
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.current_sum;
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calories.push(last_elf);
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calories.sort();
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calories.iter().rev().take(3).sum()
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}
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fn parse_input(pathname: &str) -> Vec<i32> {
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file_to_lines(pathname)
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.iter()
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.map(|s| if s.is_empty() { -1 } else { s.parse().unwrap() })
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.collect()
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}
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fn main() {
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tracing_subscriber::fmt()
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.with_env_filter(EnvFilter::from_default_env())
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.with_target(false)
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.with_file(true)
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.with_line_number(true)
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.without_time()
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.compact()
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.init();
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let sample = parse_input("samples/day01.txt");
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let input = parse_input("inputs/day01.txt");
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assert_eq!(part_1(&sample), 24000);
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info!("Part 1: {}", part_1(&input));
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assert_eq!(part_2(&sample), 45000);
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info!("Part 2: {}", part_2(&input));
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}
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