110 lines
2.9 KiB
Rust
110 lines
2.9 KiB
Rust
use crate::common::AdventOfCodeDay;
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use std::collections::HashMap;
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#[derive(Debug)]
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struct Food {
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ingredients: Vec<String>,
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allergens: Vec<String>,
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}
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impl Food {
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fn parse(line: String) -> Food {
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let split = line.split(" (contains ").collect::<Vec<_>>();
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return Food {
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ingredients: split[0].split(" ").map(String::from).collect(),
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allergens: split[1].replace(")", "").split(", ").map(String::from).collect(),
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}
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}
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}
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#[derive(Debug)]
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pub struct Day21 {
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input: Vec<Food>,
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}
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impl Day21 {
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pub fn new() -> Self {
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let input_bytes = include_bytes!("../res/21_input.txt");
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let input_str = String::from_utf8_lossy(input_bytes);
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let data = input_str
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.lines()
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.map(|p| Food::parse(String::from(p)))
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.collect::<Vec<_>>();
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Self {
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input: data
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}
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}
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}
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impl Day21 {
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fn find_allergen_candidates(&self) -> Vec<(String, Vec<String>)> {
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let mut ag_map = HashMap::<String, Vec<String>>::new();
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for food in &self.input {
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for allergen in &food.allergens {
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if let Some(candidates) = ag_map.get_mut(allergen) {
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candidates.retain(|c| food.ingredients.contains(c))
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} else {
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ag_map.insert(allergen.clone(), food.ingredients.clone());
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}
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}
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}
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loop {
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let mut changed = false;
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for rm in ag_map.iter().filter(|(_,v)| v.len()==1).map(|(_,v)| v[0].clone()).collect::<Vec<_>>() {
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for (_, cand_mut) in ag_map.iter_mut() {
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if cand_mut.len() == 1 { continue; }
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let l1 = cand_mut.len();
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cand_mut.retain(|v| *v != rm);
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if cand_mut.len() != l1 { changed = true; }
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}
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}
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if !changed { break; }
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}
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return ag_map.iter().map(|(k,v)| (k.clone(), v.clone())).collect::<Vec<_>>();
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}
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}
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impl AdventOfCodeDay for Day21 {
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fn task_1(&self) -> String {
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//for v in &self.input { verboseln!("{:?}", v); }
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let candidates = self.find_allergen_candidates();
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if is_verbose!() {
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for (k,v) in &candidates { verboseln!("{: <9} ({}) := {:?}", k, v.len(), v); }
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}
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let allergen_ingred = candidates.iter().flat_map(|p| p.1.iter() ).collect::<Vec<_>>();
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return self.input.iter().flat_map(|p| p.ingredients.iter()).filter(|ig| !allergen_ingred.contains(&ig)).count().to_string();
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}
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fn task_2(&self) -> String {
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let mut candidates = self.find_allergen_candidates();
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candidates.sort_by(|a,b| a.0.cmp(&b.0));
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if is_verbose!() {
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for (k,v) in &candidates { verboseln!("{: <9} ({}) := {:?}", k, v.len(), v); }
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}
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return candidates.iter().map(|(_,v)|v[0].clone()).collect::<Vec<String>>().join(",");
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}
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} |