rust day 23

Author: OrangeBacon

src/days/day20.rs

@@ -34,14 +34,15 @@ impl Tile {
             adj.swap(0, 2);
         }
         adj.rotate_right(self.rotation);
-        adj[side].get(0).map(|x|x.id)
+        adj[side].get(0).map(|x| x.id)
     }
 
     /// applies flips and rotation until side side == id
     fn set_transform(&mut self, side: usize, id: usize, side2: usize, id2: usize) {
         let mut adj = self.adjacency.to_vec();
         for i in 0..4 {
-            if ((id == 0 && adj[side].is_empty()) || (!adj[side].is_empty() && adj[side][0].id == id))
+            if ((id == 0 && adj[side].is_empty())
+                || (!adj[side].is_empty() && adj[side][0].id == id))
                 && ((id2 == 0 && adj[side2].is_empty())
                     || (!adj[side2].is_empty() && adj[side2][0].id == id2))
             {
@@ -53,7 +54,8 @@ impl Tile {
         adj.swap(0, 2);
         self.flip = true;
         for i in 0..4 {
-            if ((id == 0 && adj[side].is_empty()) || (!adj[side].is_empty() && adj[side][0].id == id))
+            if ((id == 0 && adj[side].is_empty())
+                || (!adj[side].is_empty() && adj[side][0].id == id))
                 && ((id2 == 0 && adj[side2].is_empty())
                     || (!adj[side2].is_empty() && adj[side2][0].id == id2))
             {
@@ -199,11 +201,7 @@ pub fn solve(timer: &mut Timer, input: &str) -> Result<AocResult> {
     let mut image = vec![vec![0usize; image_size]; image_size];
 
     // first cell
-    image[0][0] = adjacency_sums
-        .iter()
-        .find(|(_, v)| *v == 2)
-        .unwrap()
-        .0;
+    image[0][0] = adjacency_sums.iter().find(|(_, v)| *v == 2).unwrap().0;
     input[&image[0][0]].borrow_mut().set_transform(0, 0, 3, 0);
 
     // first row

src/days/day21.rs

@@ -28,16 +28,17 @@ pub fn solve(timer: &mut Timer, input: &str) -> Result<AocResult> {
     for line in input.iter() {
         for allergen in &line.allergens {
             if let Some(current) = ingredients.get(allergen) {
-                let int = line.ingredients.iter().copied().collect::<HashSet<_>>()
+                let int = line
+                    .ingredients
+                    .iter()
+                    .copied()
+                    .collect::<HashSet<_>>()
                     .intersection(current)
                     .copied()
                     .collect();
                 ingredients.insert(allergen, int);
             } else {
-                ingredients.insert(
-                    allergen,
-                    line.ingredients.iter().copied().collect(),
-                );
+                ingredients.insert(allergen, line.ingredients.iter().copied().collect());
             }
         }
     }
@@ -63,10 +64,7 @@ pub fn solve(timer: &mut Timer, input: &str) -> Result<AocResult> {
 
     let mut mappings = BTreeMap::new();
     for _ in 0..ingredients.len() {
-        let (name, ones) = ingredients
-            .iter()
-            .find(|&(_, x)| x.len() == 1)
-            .unwrap();
+        let (name, ones) = ingredients.iter().find(|&(_, x)| x.len() == 1).unwrap();
         let value = *ones.iter().next().unwrap();
 
         mappings.insert(*name, value);

src/days/day23.rs

@@ -0,0 +1,122 @@
+use anyhow::Result;
+use libaoc::{aoc, AocResult, Timer};
+use std::fmt;
+
+struct LinkedList {
+    indicies: Vec<usize>,
+}
+
+impl LinkedList {
+    fn from(data: &[usize]) -> Self {
+        let mut indicies = vec![(0, 0); data.len()];
+        for (i, num) in indicies.iter_mut().enumerate() {
+            *num = (data[i], *data.get(i + 1).unwrap_or(&data[0]) - 1)
+        }
+        indicies.sort_unstable_by(|&(a, _), &(b, _)| a.cmp(&b));
+        let indicies: Vec<_> = indicies.iter().map(|&(_, i)| i).collect();
+        LinkedList { indicies }
+    }
+
+    fn remove_after(&mut self, start: usize, count: usize) -> usize {
+        let ret = self.indicies[start];
+
+        let mut end = start;
+        for _ in 0..=count {
+            end = self.indicies[end];
+        }
+
+        self.indicies[start] = end;
+
+        ret
+    }
+
+    fn insert_after(&mut self, index: usize, data_ptr: usize, data_len: usize) {
+        let mut end = data_ptr;
+        for _ in 0..(data_len - 1) {
+            end = self.indicies[end];
+        }
+
+        self.indicies[end] = self.indicies[index];
+
+        self.indicies[index] = data_ptr;
+    }
+
+    fn to_vec(&self) -> Vec<usize> {
+        let mut result = Vec::with_capacity(self.indicies.len());
+        result.push(1);
+
+        let mut index = 0;
+        for _ in 0..(self.indicies.len() - 1) {
+            let data = self.indicies[index];
+            result.push(data + 1);
+            index = data
+        }
+
+        result
+    }
+}
+
+impl fmt::Debug for LinkedList {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        write!(f, "{:?}", self.to_vec())
+    }
+}
+
+fn game(cups: &[usize], move_count: usize) -> LinkedList {
+    let max = cups.len();
+    let mut current_cup = cups[0] - 1;
+    let mut cups = LinkedList::from(cups);
+
+    for _ in 0..move_count {
+        let c1 = cups.indicies[current_cup];
+        let c2 = cups.indicies[c1];
+        let c3 = cups.indicies[c2];
+        let moved_cups = [c1 + 1, c2 + 1, c3 + 1];
+
+        let removed = cups.remove_after(current_cup, 3);
+
+        let mut destination = current_cup;
+        loop {
+            if destination == 0 {
+                destination = max;
+            }
+            if moved_cups.contains(&destination) {
+                destination -= 1
+            } else {
+                break;
+            }
+        }
+
+        cups.insert_after(destination - 1, removed, 3);
+
+        current_cup = cups.indicies[current_cup];
+    }
+
+    cups
+}
+
+#[aoc("82635947", "157047826689", "685974213")]
+pub fn solve(timer: &mut Timer, input: &str) -> Result<AocResult> {
+    let mut cups: Vec<_> = input
+        .chars()
+        .map(|x| x.to_digit(10).unwrap() as usize)
+        .collect();
+    timer.lap("Parse");
+
+    let mut part1 = game(&cups, 100).to_vec();
+    while part1[0] != 1 {
+        part1.rotate_right(1);
+    }
+    let part1 = part1[1..]
+        .iter()
+        .fold(String::new(), |s, &c| s + &c.to_string());
+    timer.lap("Part 1");
+
+    cups.extend(10..=1_000_000);
+    let part2 = game(&cups, 10_000_000);
+    let part2 = (part2.indicies[0]+1) * (part2.indicies[part2.indicies[0]]+1);
+
+    timer.lap("Part 2");
+
+    Ok(AocResult::new(part1, part2))
+}

src/days/mod.rs

@@ -20,3 +20,4 @@ mod day19;
 mod day20;
 mod day21;
 mod day22;
+mod day23;