From aadb672532b457c9aebcd34af158c4295aea96c0 Mon Sep 17 00:00:00 2001
From: Tobias Marschner <contact@tobiasm.dev>
Date: Wed, 10 Apr 2024 09:56:02 +0200
Subject: [PATCH] Touches on 2022/day19-part1

---
 2022/day19-part1/src/main.rs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/2022/day19-part1/src/main.rs b/2022/day19-part1/src/main.rs
index eed6914..cdea3b0 100644
--- a/2022/day19-part1/src/main.rs
+++ b/2022/day19-part1/src/main.rs
@@ -13,6 +13,8 @@ struct Blueprint {
     optimal_geode_count: u16,
 }
 
+const TOTAL_RUNTIME: usize = 24;
+
 impl Blueprint {
     // Solve the given blueprint using BFS.
     fn solve_bfs(&mut self) {
@@ -37,7 +39,7 @@ impl Blueprint {
         // Iterate over all timeslots.
         // Building a robot at t=1 cannot influence the final geode-count,
         // so it's omitted from the simulation here.
-        for ts in (2usize..=24).rev() {
+        for ts in (2usize..=TOTAL_RUNTIME).rev() {
             // println!("Now at {} remaining time. Processing {} input RSs ...", ts, next_hs.len());
 
             // Process every RS of the past timeslot
@@ -163,7 +165,7 @@ impl RecursionState {
 
 // Copy over states for the next simulation round, pruning a lot of (but not all) 
 //   RecursionStates that are "strictly inferior" in terms of Pareto optimality.
-// Will clear any previously present elements in dest.
+// Will clear any previously present elements in `dest`.
 //
 // A few words on the general idea here:
 // The goal here is to check for Pareto improvements. An example:
@@ -182,9 +184,6 @@ fn prune_states(source: &mut [RecursionState], dest: &mut Vec<RecursionState>) {
     // Begin by sorting the source lexicrgraphically and clearing the destination.
     source.sort_unstable();
     dest.clear();
-    // Add one more element to the source, at the very end,
-    // that is a copy of the last element +1 ore.
-    // This is to ensure that the actual last element
     // Iterate through it from smallest to largest element and look at every pair of states.
     for (a, b) in source.iter().zip(source.iter().skip(1)) {
         // Don't copy a over if it is strictly inferior or equal to b.
@@ -201,7 +200,7 @@ fn prune_states(source: &mut [RecursionState], dest: &mut Vec<RecursionState>) {
             dest.push(*a);
         }
     }
-    // Copy over the very last element, guaranteed to be part of the frontier.
+    // Copy over the very last element, too.
     dest.push(*source.last().unwrap());
 }
 
@@ -235,7 +234,7 @@ fn main() {
 
     // Solve for every blueprint.
     for bp in &mut blueprints {
-        // Solve every blueprint with 24 minutes of time.
+        // Solve every blueprint with TOTAL_RUNTIME minutes of time.
         println!("Solving Blueprint {}", bp.id);
         bp.solve_bfs();
     }