From 0665e109af61cfa41cb92604daa96433baeb65bb Mon Sep 17 00:00:00 2001
From: Keenan Tims <ktims@demonware.net>
Date: Wed, 6 Dec 2023 11:07:40 -0800
Subject: [PATCH] day5: performance: don't iterate to position just do
 arithemtic

---
 5/src/main.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/5/src/main.rs b/5/src/main.rs
index ec29177..977b59b 100644
--- a/5/src/main.rs
+++ b/5/src/main.rs
@@ -163,10 +163,7 @@ impl From<&str> for AlmanacMapping {
 impl AlmanacMapping {
     fn lookup(&self, key: u64) -> Option<u64> {
         if self.source_range.contains(&key) {
-            match self.source_range.clone().position(|x| x == key) {
-                Some(i) => self.dest_range.clone().nth(i),
-                None => None,
-            }
+            Some(self.dest_range.start + (key - self.source_range.start))
         } else {
             None
         }