day8: part1 solution

src/day8.rs

@@ -1,12 +1,6 @@
-use std::{
+use std::{f64, fmt::Display};
-    collections::{HashMap, HashSet},
-    f64,
-    fmt::{Display, Write},
-    iter::repeat_n,
-};
 
 use aoc_runner_derive::{aoc, aoc_generator};
-use cached::proc_macro::cached;
 use itertools::Itertools;
 
 #[derive(Eq, PartialEq, Clone, Debug, Hash)]
@@ -55,7 +49,6 @@ impl From<&str> for Junction {
 struct Circuits {
     junctions: Vec<Junction>,
     circuits: Vec<Vec<usize>>,
-    checked: HashSet<(usize, usize)>,
 }
 
 impl Circuits {
@@ -79,7 +72,6 @@ impl Circuits {
     fn connect(&mut self, a: usize, b: usize) {
         let a_circuit = self.find_circuit(a);
         let b_circuit = self.find_circuit(b);
-        self.checked.insert((a, b));
 
         match (a_circuit, b_circuit) {
             (None, None) => self.circuits.push(vec![a, b]), // both are unconnected
@@ -99,38 +91,39 @@ fn parse(input: &str) -> Circuits {
     Circuits {
         junctions,
         circuits: Vec::new(),
-        checked: HashSet::new(),
     }
 }
 
-#[aoc(day8, part1)]
+fn part1_impl(input: &Circuits, n: usize) -> u64 {
-fn part1(input: &Circuits) -> u64 {
     let mut circuits = input.clone();
-    for (a, b, d) in circuits
+    for (a, b, _d) in circuits
         .junctions
         .iter()
         .enumerate()
         .combinations(2)
         .map(|p| (p[0].0, p[1].0, p[0].1.distance(p[1].1)))
         .sorted_by(|a, b| a.2.partial_cmp(&b.2).unwrap())
-        .take(1000)
+        .take(n)
     {
-        println!(
-            "connecting {} <-> {} = {d}",
-            circuits.junctions[a], circuits.junctions[b]
-        );
         circuits.connect(a, b)
     }
-    println!("{:?}", circuits.circuits);
+
     circuits
         .circuits
         .iter()
+        .sorted_by_key(|c| c.len())
+        .rev()
         .take(3)
         .map(|c| c.len())
         .reduce(|a, b| a * b)
         .unwrap() as u64
 }
 
+#[aoc(day8, part1)]
+fn part1(input: &Circuits) -> u64 {
+    part1_impl(input, 1000)
+}
+
 #[aoc(day8, part2)]
 fn part2(input: &Circuits) -> u64 {
     0
@@ -163,7 +156,7 @@ mod tests {
 
     #[test]
     fn part1_example() {
-        assert_eq!(part1(&parse(EXAMPLE)), 40);
+        assert_eq!(part1_impl(&parse(EXAMPLE), 10), 40);
     }
 
     #[test]