reduced overhead by passing an owned string

src/day03/part03a.rs

@@ -1,6 +1,6 @@
 use iter_first_max::IterFirstMaxExt;
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     puzzle.lines().for_each(|battery_bank| {