Clippy-driven cleanup

1 files changed, 14 insertions, 8 deletions

diff --git a/2022/src/bin/day_23.rs b/2022/src/bin/day_23.rs
index 1267431..44483a5 100644
--- a/2022/src/bin/day_23.rs
+++ b/2022/src/bin/day_23.rs
@@ -24,7 +24,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     }
 
     {
-        let mut elves_2 = elves.clone();
+        let mut elves_2 = elves;
         for round in 1.. {
             if !elves_2.process_round() {
                 dbg!(round);
@@ -98,17 +98,23 @@ impl ElfMap {
 
         // phase 1: figure out where each elf wants to move
         for elf in &self.elves {
-            if let Some(destination) = self.find_elf_move(&elf) {
-                if elf_moves.contains_key(&destination) {
-                    elf_moves.remove(&destination);
-                    conflict_moves.insert(destination);
-                } else if !conflict_moves.contains(&destination) {
-                    elf_moves.insert(destination, elf.clone());
+            if let Some(destination) = self.find_elf_move(elf) {
+                use std::collections::btree_map::Entry;
+                match elf_moves.entry(destination) {
+                    Entry::Occupied(elf_move_entry) => {
+                        conflict_moves.insert(elf_move_entry.key().clone());
+                        elf_move_entry.remove_entry();
+                    }
+                    Entry::Vacant(elf_move_entry) => {
+                        if !conflict_moves.contains(elf_move_entry.key()) {
+                            elf_move_entry.insert(elf.clone());
+                        }
+                    }
                 }
             }
         }
 
-        let any_elf_moved = elf_moves.len() > 0;
+        let any_elf_moved = !elf_moves.is_empty();
 
         // phase 2: move the elves
         for (dest, src) in elf_moves {