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extern crate advent_of_code_2017;
use advent_of_code_2017::*;
fn main() {
let args = AdventArgs::init();
let components: Vec<Component> = args.input.iter()
.map(|line| {
let mut split = line.split('/');
Component {
a: split.next().unwrap().parse().unwrap(),
b: split.next().unwrap().parse().unwrap()
}
})
.collect();
if args.part == 1 {
let strongest = build_strongest(0, components);
println!("{}", strongest);
} else {
let (strongest, longest) = build_longest(0, components);
println!("length: {}, strength: {}", longest, strongest);
}
}
fn build_strongest(start: u32, components: Vec<Component>) -> u32 {
components.iter().enumerate()
.filter(|&(_, c)| c.a == start || c.b == start)
.map(|(i, c)| {
let end = if c.a == start { c.b } else { c.a };
let mut subset = components.clone();
subset.remove(i);
c.strength() + build_strongest(end, subset)
}).max().unwrap_or(0)
}
fn build_longest(start: u32, components: Vec<Component>) -> (u32, u32) {
components.iter().enumerate()
.filter(|&(_, c)| c.a == start || c.b == start)
.map(|(i, c)| {
let end = if c.a == start { c.b } else { c.a };
let mut subset = components.clone();
subset.remove(i);
let (s, l) = build_longest(end, subset);
(c.strength() + s, 1 + l)
}).max_by(|&(s1, l1), &(s2, l2)| {
l1.cmp(&l2).then(s1.cmp(&s2))
}).unwrap_or((0, 0))
}
#[derive(Debug, Clone)]
struct Component {
a: u32,
b: u32
}
impl Component {
fn strength(&self) -> u32 {
self.a + self.b
}
}
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