Added AOC 2020 day 03 - 14

www/statics/aoc/2020/07_solution.rs

@@ -0,0 +1,111 @@
+use crate::common::AdventOfCodeDay;
+
+use std::collections::VecDeque;
+use std::collections::HashSet;
+use regex::Regex;
+
+#[derive(Debug)]
+struct Rule {
+    parent: String,
+    children: Vec<(usize, String)>,
+}
+
+pub struct Day07 {
+    input: Vec<Rule>,
+}
+
+fn parse_line(line: &str) -> Rule {
+    lazy_static! {
+        static ref REX_LINE:  Regex = Regex::new(r"^(?P<bag>[a-z]+ [a-z]+) bags contain (?P<inner>(?:(?:(?:[0-9]+ (?:[a-z]+ [a-z]+)) bags?(?:, |\.)?)+)|no other bags\.)$").unwrap();
+        static ref REX_INNER: Regex = Regex::new(r"(?P<num>[0-9]+) (?P<bag>[a-z]+ [a-z]+) bags?[.,]").unwrap();
+    }
+
+    if let Some(rline) = REX_LINE.captures(line) {
+        let parent = rline.name("bag").unwrap().as_str().to_owned();
+
+        if rline.name("inner").unwrap().as_str() == "not other bags." {
+            return Rule {
+                parent: parent,
+                children: vec![],
+            }
+        }
+
+        let childs = REX_INNER
+                        .captures_iter(rline.name("inner").unwrap().as_str())
+                        .map(|p| (p.name("num").unwrap().as_str().parse::<usize>().unwrap(), p.name("bag").unwrap().as_str().to_owned()))
+                        .collect::<Vec<(usize, String)>>();
+
+        return Rule {
+            parent: parent,
+            children: childs,
+        }
+    } else {
+        panic!(format!("no regex line match: '{}'", line.to_owned()));
+    }
+
+}
+
+impl Day07 {
+    pub fn new() -> Self {
+        let input_bytes = include_bytes!("../res/07_input.txt");
+        let input_str = String::from_utf8_lossy(input_bytes);
+        
+        let data = input_str
+                        .lines()
+                        .map(parse_line)
+                        .collect::<Vec<Rule>>();
+
+        Self {
+            input: data
+        }
+    }
+
+    fn find_rule(&self, bag: &str) -> Option<&Rule> {
+        for r in &self.input {
+            if r.parent == bag {
+                return Some(r);
+            }
+        }
+        return None;
+    }
+    
+    fn can_contain(&self, parent: &str, child: &str) -> bool {
+        let mut candidates: VecDeque<String> = VecDeque::new();
+        let mut visited: HashSet<String> = HashSet::new();
+    
+        candidates.push_back(parent.to_owned());
+        visited.insert(parent.to_owned());
+    
+        while !candidates.is_empty() {
+            let cand = candidates.pop_back().unwrap();
+            if let Some(rule) = self.find_rule(cand.as_str()) {
+                for rulechild in &rule.children {
+                    let rcname = rulechild.1.to_owned();
+                    if rcname == child {
+                        return true;
+                    } else if !visited.contains(&rcname) {
+                        candidates.push_back(rcname.to_owned());
+                        visited.insert(rcname);
+                    }
+                }
+            }
+        }
+    
+        return false;
+    }
+
+    fn get_full_children_count(&self, name: &str) -> usize {
+        self.find_rule(name).unwrap().children.iter().map(|p| p.0 + p.0 * self.get_full_children_count(&p.1)).sum()
+    }
+}
+
+impl AdventOfCodeDay for Day07 {
+
+    fn task_1(&self) -> String {
+        self.input.iter().filter(|p| self.can_contain(p.parent.as_str(), "shiny gold")).count().to_string()
+    }
+
+    fn task_2(&self) -> String  {
+        self.get_full_children_count("shiny gold").to_string()
+    }
+}