From 8a61db424bb56fcd763a05d04bb1912527643673 Mon Sep 17 00:00:00 2001
From: StNicolay <stnicolay2007@mail.ru>
Date: Sat, 7 Dec 2024 10:58:10 +0300
Subject: [PATCH] Day 7 but math

---
 src/day7.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/day7.rs b/src/day7.rs
index a65cd85..6a9a440 100644
--- a/src/day7.rs
+++ b/src/day7.rs
@@ -10,13 +10,16 @@ enum Operation {
 }
 
 impl Operation {
+    #[allow(clippy::pedantic)]
     fn apply(self, a: u64, b: u64) -> u64 {
         match self {
             Self::Add => a + b,
             Self::Mul => a * b,
             Self::Concentration => {
-                let val = format!("{a}{b}");
-                val.parse().unwrap()
+                if b == 0 {
+                    return a * 10;
+                }
+                (a * 10_u64.pow((b as f64).log10() as u32 + 1)) + b
             }
         }
     }