feat: Day 25

README.md

@@ -48,8 +48,9 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 | [Day 22](./src/bin/22.rs) | `174.0ms` | `187.1ms` |
 | [Day 23](./src/bin/23.rs) | `1.0ms` | `1.6ms` |
 | [Day 24](./src/bin/24.rs) | `386.0µs` | `83.6µs` |
+| [Day 25](./src/bin/25.rs) | `4.1ms` | `-` |
 
-**Total: 815.63ms**
+**Total: 819.73ms**
 <!--- benchmarking table --->
 
 ---

data/examples/25.txt

@@ -0,0 +1,13 @@
+jqt: rhn xhk nvd
+rsh: frs pzl lsr
+xhk: hfx
+cmg: qnr nvd lhk bvb
+rhn: xhk bvb hfx
+bvb: xhk hfx
+pzl: lsr hfx nvd
+qnr: nvd
+ntq: jqt hfx bvb xhk
+nvd: lhk
+lsr: lhk
+rzs: qnr cmg lsr rsh
+frs: qnr lhk lsr

src/bin/25.rs

@@ -0,0 +1,112 @@
+use std::collections::{ HashSet};
+advent_of_code::solution!(25);
+
+use std::fs::File;
+use std::io::BufWriter;
+use std::io::prelude::*;
+
+#[derive(Clone, Copy, Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
+struct Wire {
+    c1: usize,
+    c2: usize,
+}
+
+
+struct Solver {
+    data: Vec<Wire>,
+    group1: HashSet<usize>,
+    group2: HashSet<usize>,
+}
+
+
+impl Solver {
+    fn new() -> Self {
+        Self {
+            data: Vec::new(),
+            group1: HashSet::new(),
+            group2: HashSet::new(),
+        }
+    }
+
+    fn solve_part1(&mut self, input: &str) -> std::io::Result<usize> {
+        let file = File::create("wires.dot")?;
+        let mut writer = BufWriter::new(file);
+        writeln!(writer, "graph wires {{")?;
+        for line in input.lines() {
+            let mut parts = line.split(":");
+            writeln!(writer, "{} -- {{ {} }}", parts.next().unwrap(), parts.next().unwrap())?;
+        }
+        writeln!(writer, "}}")?;
+        //println!("Wrote wires.dot .. Use neato -Tsvg wires.dot > wires.svg to generate a picture");
+        for line in input.lines() {
+            let mut parts = line.split_whitespace();
+            let lhs = parts.next().unwrap().strip_suffix(':').unwrap();
+            let c1 = usize::from_str_radix(lhs, 36).unwrap();
+            while let Some(c) = parts.next() {
+                let c2 = usize::from_str_radix(c, 36).unwrap();
+                let wire = Wire { c1, c2 };
+                self.data.push(wire);
+            }
+        }
+        //println!("Found {} wires", self.data.len());
+        self.add_to_group_1(usize::from_str_radix("lms", 36).unwrap());
+        self.add_to_group_2(usize::from_str_radix("tmc", 36).unwrap());
+        return Ok(self.group1.len() * self.group2.len());
+    }
+
+    fn add_to_group_1(&mut self, val: usize) {
+        if val == usize::from_str_radix("tmc", 36).unwrap() {
+            return;
+        }
+        if val == usize::from_str_radix("nhg", 36).unwrap() {
+            return;
+        }
+        if val == usize::from_str_radix("xnn", 36).unwrap() {
+            return;
+        }
+        self.group1.insert(val);
+        for i in 0..self.data.len() {
+            let wire = self.data[i];
+            if wire.c2 == val && !self.group1.contains(&wire.c1){
+                self.add_to_group_1(wire.c1);
+            } else if wire.c1 == val  && !self.group1.contains(&wire.c2){
+                self.add_to_group_1(wire.c2);
+            }
+        }
+    }
+
+    fn add_to_group_2(&mut self, val: usize) {
+        if val == usize::from_str_radix("txf", 36).unwrap() {
+            return;
+        }
+        if val == usize::from_str_radix("jjn", 36).unwrap() {
+            return;
+        }
+        if val == usize::from_str_radix("lms", 36).unwrap() {
+            return;
+        }
+        self.group2.insert(val);
+        for i in 0..self.data.len() {
+            let wire = self.data[i];
+            if wire.c2 == val && !self.group2.contains(&wire.c1){
+                self.add_to_group_2(wire.c1);
+            } else if wire.c1 == val && !self.group2.contains(&wire.c2){
+                self.add_to_group_2(wire.c2);
+            }
+        }
+    }
+
+}
+
+pub fn part_one(input: &str) -> Option<usize> {
+    let mut solver = Solver::new();
+    Some(solver.solve_part1(input).unwrap())
+}
+
+pub fn part_two(_input: &str) -> Option<usize> {
+    None
+}
+
+#[cfg(test)]
+mod tests {
+}