summaryrefslogtreecommitdiff
path: root/src/bin/day16.rs
blob: 48295ce37339ae3f1887f4f9b3c888639d4de40d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
use std::collections::HashMap;
use regex::Regex;

fn main() {
    let input = advent::read_lines(16);
    let search = HashMap::from([
        ("children", 3),
        ("cats", 7),
        ("samoyeds", 2),
        ("pomeranians", 3),
        ("akitas", 0),
        ("vizslas", 0),
        ("goldfish", 5),
        ("trees", 3),
        ("cars", 2),
        ("perfumes", 1),
    ]);
    println!("16a: {}", find_aunt(&input, &search, false));
    println!("16b: {}", find_aunt(&input, &search, true));
}

struct Aunt {
    name: u16,
    attributes: HashMap<String, u8>,
}

impl Aunt {
    fn new(input: &str) -> Aunt {
        let re = Regex::new(r"([a-z]+): ([0-9]+)").unwrap();
        let re_aunt = Regex::new(r"^Sue ([0-9]+):").unwrap();

        let name = re_aunt.captures(input).unwrap()[1].parse::<u16>().unwrap();

        let mut aunt = Aunt {
            name,
            attributes: HashMap::new(),
        };

        for cap in re.captures_iter(input) {
            let attribute = cap[1].to_string();
            let amount = cap[2].parse::<u8>().unwrap();
            aunt.attributes.insert(attribute, amount);
        }

        aunt
    }

    fn has_attributes(&self, attributes: &HashMap<&str, u8>, outdated: bool) -> bool {
        if outdated {
            self.has_attributes_v2(attributes)
        } else {
            self.has_attributes_v1(attributes)
        }
    }

    fn has_attributes_v1(&self, attributes: &HashMap<&str, u8>) -> bool {
        for (attr, val) in attributes {
            if let Some(myval) = self.attributes.get(*attr) {
                if myval != val {
                    /* found non-matching attribute */
                    return false;
                }
            }
        }
        true
    }

    fn has_attributes_v2(&self, attributes: &HashMap<&str, u8>) -> bool {
        for (attr, val) in attributes {
            if let Some(myval) = self.attributes.get(*attr) {
                match attr {
                    x if ["cats", "trees"].contains(x) => if myval <= val { return false; },
                    x if ["pomeranians", "goldfish"].contains(x) => if myval >= val { return false; },
                    _ => if myval != val { return false; }
                }
            }
        }
        true
    }
}

fn find_aunt(input: &[String], search: &HashMap<&str, u8>, outdated: bool) -> u16 {
    input.iter()
         .map(|x| Aunt::new(x))
         .find(|x| x.has_attributes(search, outdated))
         .unwrap()
         .name
}