chore: tidy

Author: clechasseur

aoclp_solutions/src/y2025/day_09.rs

@@ -3,11 +3,11 @@ use std::collections::BTreeSet;
 use std::iter::successors;
 
 use aoclp::positioning::direction::four_points::Direction4;
+use aoclp::positioning::direction::{Direction, MovementDirection};
 use aoclp::positioning::pt::{rectangular_area, Pt};
 use aoclp::solvers_impl::input::safe_get_input_as_many;
-use itertools::{chain, Either, Itertools};
+use itertools::Itertools;
 use strum::IntoEnumIterator;
-use aoclp::positioning::direction::{Direction, MovementDirection};
 
 pub fn part_1() -> i64 {
     input()
@@ -61,7 +61,9 @@ fn build_red_zone(red_tiles: &[Pt]) -> impl Iterator<Item = Pt> + use<'_> {
 
     let get_direction = |a: Pt, b: Pt| {
         let displacement = Pt::new((b.x - a.x).signum(), (b.y - a.y).signum());
-        Direction4::iter().find(|&d| d.displacement() == displacement).unwrap()
+        Direction4::iter()
+            .find(|&d| d.displacement() == displacement)
+            .unwrap()
     };
 
     red_tiles
@@ -75,26 +77,23 @@ fn build_red_zone(red_tiles: &[Pt]) -> impl Iterator<Item = Pt> + use<'_> {
             let direction = get_direction(a, b);
             let turning_left = get_direction(b, c) == direction.turn_left();
 
-            let red_zone_path = successors(Some(a), move |&p| {
+            let tail = if turning_left {
+                vec![]
+            } else {
+                vec![
+                    b + direction.turn_left(),
+                    b + direction + direction.turn_left(),
+                    b + direction,
+                ]
+            };
+
+            successors(Some(a), move |&p| {
                 let next = p + direction;
                 (next != b).then_some(next)
             })
-                .skip(1)
-                .map(move |p| p + (direction.turn_left()))
-                .collect_vec();
-
-            if turning_left {
-                Either::Left(red_zone_path.into_iter())
-            } else {
-                Either::Right(chain(
-                    red_zone_path,
-                    vec![
-                        b + direction.turn_left(),
-                        b + direction + direction.turn_left(),
-                        b + direction,
-                    ],
-                ))
-            }
+            .skip(1)
+            .map(move |p| p + (direction.turn_left()))
+            .chain(tail)
         })
 }