day18: formatting and cleanup

18/src/main.rs

@@ -1,9 +1,7 @@
 use itertools::Itertools;
-use std::collections::{HashMap, LinkedList};
-use std::fmt::{Display, Write};
+use std::collections::LinkedList;
 use std::fs::File;
 use std::io::{BufRead, BufReader, Lines};
-use std::ops::Range;
 use std::time::Instant;
 
 // BOILERPLATE
@@ -47,12 +45,7 @@ enum Turn {
 
 impl Direction {
     const fn all() -> &'static [Self; 4] {
-        &[
-            Direction::Left,
-            Direction::Right,
-            Direction::Up,
-            Direction::Down,
-        ]
+        &[Direction::Left, Direction::Right, Direction::Up, Direction::Down]
     }
     const fn opposite(&self) -> Self {
         match self {
@@ -127,13 +120,7 @@ impl From<&str> for DigInstruction {
         let (dir, count, color) = (
             parts.next().unwrap(),
             parts.next().unwrap(),
-            parts
-                .next()
-                .unwrap()
-                .chars()
-                .skip(2)
-                .take(6)
-                .collect::<String>(),
+            parts.next().unwrap().chars().skip(2).take(6).collect::<String>(),
         );
         Self {
             dir: dir.into(),
@@ -152,7 +139,7 @@ impl DigInstruction {
             "1" => Direction::Down,
             "2" => Direction::Left,
             "3" => Direction::Up,
-            s => panic!("`{}` is not a valid direction code", s)
+            s => panic!("`{}` is not a valid direction code", s),
         };
     }
 }
@@ -177,9 +164,7 @@ struct DigTile {
 
 impl Default for DigTile {
     fn default() -> Self {
-        Self {
-            position: (0, 0),
-        }
+        Self { position: (0, 0) }
     }
 }
 
@@ -188,9 +173,6 @@ type Position = (isize, isize);
 #[derive(Debug)]
 struct DigHole {
     tiles_loop: LinkedList<DigTile>,
-    tiles_map: HashMap<Position, DigTile>,
-    x_range: Range<isize>,
-    y_range: Range<isize>,
     area: u64,
 }
 
@@ -203,9 +185,6 @@ impl DigHole {
     fn new() -> Self {
         DigHole {
             tiles_loop: LinkedList::new(),
-            tiles_map: HashMap::new(),
-            x_range: 0..0,
-            y_range: 0..0,
             area: 0,
         }
     }
@@ -215,9 +194,7 @@ impl DigHole {
     fn run_plan(&mut self, plan: &DigPlan) {
         let mut cur_pos = (0, 0);
 
-        self.tiles_loop.push_back(DigTile {
-            position: cur_pos,
-        });
+        self.tiles_loop.push_back(DigTile { position: cur_pos });
         let mut move_offset;
         for (idx, i) in plan.instructions.iter().enumerate() {
             let prev_instruction = if idx > 0 {
@@ -225,17 +202,14 @@ impl DigHole {
             } else {
                 &plan.instructions[plan.instructions.len() - 1]
             };
-            let Some(next_instruction) = plan
-                .instructions
-                .get(idx + 1)
-                .or(Some(&plan.instructions[0]))
-            else {
+            let Some(next_instruction) = plan.instructions.get(idx + 1).or(Some(&plan.instructions[0])) else {
                 panic!()
             };
             let cur_turn = prev_instruction.dir.turn_kind(i.dir);
             let next_turn = i.dir.turn_kind(next_instruction.dir);
-            // point needs to live on the 'outside' corner of the character. to
-            // achieve this we need to offset the move by the following
+
+            // Point needs to live on the 'outside' corner of the character. to achieve this we need to offset the move
+            // by the following. Found this empirically but there's probably some mathematical principle behind it...
             move_offset = match (cur_turn, next_turn) {
                 (Turn::RightNinety, Turn::RightNinety) => 1,
                 (Turn::RightNinety, Turn::LeftNinety) => 0,
@@ -244,14 +218,8 @@ impl DigHole {
                 t => panic!("turn {:?} not allowed here", t),
             };
 
-            cur_pos = self.pos_offset_n(
-                cur_pos,
-                i.dir.offset(),
-                (i.count as isize + move_offset) as usize,
-            );
-            self.tiles_loop.push_back(DigTile {
-                position: cur_pos,
-            });
+            cur_pos = self.pos_offset_n(cur_pos, i.dir.offset(), (i.count as isize + move_offset) as usize);
+            self.tiles_loop.push_back(DigTile { position: cur_pos });
         }
 
         // Shoelace formula
@@ -266,36 +234,15 @@ impl DigHole {
     }
 }
 
-impl Display for DigHole {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        for y in self.y_range.clone() {
-            for x in self.x_range.clone() {
-                f.write_char(if (x, y) == (133, -267) {
-                    '*'
-                } else if self.tiles_map.contains_key(&(x, y)) {
-                    '#'
-                } else {
-                    '.'
-                })?;
-            }
-            writeln!(f)?;
-        }
-        Ok(())
-    }
-}
-
 impl<T: BufRead> From<Lines<T>> for DigPlan {
     fn from(lines: Lines<T>) -> Self {
         Self {
-            instructions: lines
-                .map(|line| DigInstruction::from(line.unwrap().as_str()))
-                .collect(),
+            instructions: lines.map(|line| DigInstruction::from(line.unwrap().as_str())).collect(),
         }
     }
 }
 
 // PROBLEM 1 solution
-
 fn problem1<T: BufRead>(input: Lines<T>) -> u64 {
     let plan = DigPlan::from(input);
     let mut dig = DigHole::new();