From 9d49d5037566587ae33f34759e85592b8a207d7e Mon Sep 17 00:00:00 2001
From: Greg Burri <greg.burri@gmail.com>
Date: Fri, 9 Dec 2022 14:32:17 +0100
Subject: [PATCH] A bit more readable
---
src/day09.rs | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/src/day09.rs b/src/day09.rs
index 6fd0b50..193d7cb 100644
--- a/src/day09.rs
+++ b/src/day09.rs
@@ -48,19 +48,24 @@ pub fn nb_positions_visited_by_tail<const N: usize>(movements: &[Movement]) -> u
// 2) Move the rest of the rope.
for i in (0..N-1).rev() {
let target = rope[i+1];
- let mut node = &mut rope[i];
+ let mut node = rope[i];
+
let (dx, dy): (i32, i32) = (node.0 - target.0, node.1 - target.1);
let (dx_abs, dy_abs) = (dx.abs(), dy.abs());
+
if dx_abs == 2 && dy_abs == 2 {
- (node.0, node.1) = (target.0 + dx.signum(), target.1 + dy.signum());
+ node = (target.0 + dx.signum(), target.1 + dy.signum());
} else if dx_abs >= 2 {
- (node.0, node.1) = (target.0 + dx.signum(), target.1);
+ node = (target.0 + dx.signum(), target.1);
} else if dy_abs >= 2 {
- (node.0, node.1) = (target.0, target.1 + dy.signum());
+ node = (target.0, target.1 + dy.signum());
}
- if i == 0 {
- visited.insert(*node);
+
+ if i == 0 && node != rope[i] {
+ visited.insert(node);
}
+
+ rope[i] = node;
}
}
};
--
2.49.0