diff --git a/README.md b/README.md
index cdafd9b..c622d5c 100644
--- a/README.md
+++ b/README.md
@@ -1,27 +1,27 @@
 # Advent of Code 2025
 ```bash
-day01:A =>            1150  (    98us)
-day01:B =>            1150  (   100us)
-day02:A =>     31839939622  ( 13822us)
-day02:B =>     41662374059  (128425us)
-day03:A =>           16812  (   119us)
-day03:B => 166345822896410  (   357us)
-day04:A =>            1518  (   321us)
-day04:B =>            8665  (  5870us)
-day05:A =>             701  (   310us)
-day05:B => 352340558684863  (    36us)
-day06:A =>   6503327062445  (   266us)
-day06:B =>   9640641878593  (   145us)
-day07:A =>            1678  (    57us)
-day07:B => 357525737893560  (    70us)
+day01:A =>            1150  (    35us)
+day01:B =>            1150  (    34us)
+day02:A =>     31839939622  (  5852us)
+day02:B =>     41662374059  ( 49642us)
+day03:A =>           16812  (    45us)
+day03:B => 166345822896410  (   136us)
+day04:A =>            1518  (   133us)
+day04:B =>            8665  (  2174us)
+day05:A =>             701  (   111us)
+day05:B => 352340558684863  (    13us)
+day06:A =>   6503327062445  (   113us)
+day06:B =>   9640641878593  (    53us)
+day07:A =>            1678  (    22us)
+day07:B => 357525737893560  (    28us)
 day08:A =>               0  (     0us)
 day08:B =>               0  (     0us)
-day09:A =>      4725826296  (   236us)
+day09:A =>      4725826296  (   105us)
 day09:B =>               0  (     0us)
-day10:A =>             452  (   667us)
+day10:A =>             452  (   271us)
 day10:B =>               0  (     0us)
-day11:A =>             636  (   491us)
-day11:B =>             636  (   421us)
+day11:A =>             636  (   192us)
+day11:B =>             636  (   162us)
                             ----------
-                             152155us
+                              59331us
 ```
\ No newline at end of file
diff --git a/src/day01/mod.rs b/src/day01/mod.rs
index 8df9c19..829ddcc 100644
--- a/src/day01/mod.rs
+++ b/src/day01/mod.rs
@@ -18,11 +18,11 @@ L82";
 
     #[test]
     fn part01a() {
-        assert_eq!(part01a::solve(PUZZLE.to_string()), 3);
+        assert_eq!(part01a::solve(PUZZLE), 3);
     }
 
     #[test]
     fn part01b() {
-        assert_eq!(part01b::solve(PUZZLE.to_string()), 6);
+        assert_eq!(part01b::solve(PUZZLE), 6);
     }
 }
\ No newline at end of file
diff --git a/src/day01/part01a.rs b/src/day01/part01a.rs
index 11801ff..d8c4516 100644
--- a/src/day01/part01a.rs
+++ b/src/day01/part01a.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     let mut dial: i32 = 50;
diff --git a/src/day01/part01b.rs b/src/day01/part01b.rs
index c82fa72..23cc078 100644
--- a/src/day01/part01b.rs
+++ b/src/day01/part01b.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     let mut dial: i32 = 50;
diff --git a/src/day02/mod.rs b/src/day02/mod.rs
index d8aa66c..9fdf825 100644
--- a/src/day02/mod.rs
+++ b/src/day02/mod.rs
@@ -9,11 +9,11 @@ mod tests {
 
     #[test]
     fn part02a() {
-        assert_eq!(part02a::solve(PUZZLE.to_string()), 1227775554);
+        assert_eq!(part02a::solve(PUZZLE), 1227775554);
     }
 
     #[test]
     fn part02b() {
-        assert_eq!(part02b::solve(PUZZLE.to_string()), 4174379265);
+        assert_eq!(part02b::solve(PUZZLE), 4174379265);
     }
 }
\ No newline at end of file
diff --git a/src/day02/part02a.rs b/src/day02/part02a.rs
index 40efe3e..49be90e 100644
--- a/src/day02/part02a.rs
+++ b/src/day02/part02a.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     puzzle.split(",").for_each(|id_range| {
diff --git a/src/day02/part02b.rs b/src/day02/part02b.rs
index 710f8a3..41e3e72 100644
--- a/src/day02/part02b.rs
+++ b/src/day02/part02b.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     puzzle.split(",").for_each(|id_range| {
diff --git a/src/day03/mod.rs b/src/day03/mod.rs
index 64289a0..f9d7d36 100644
--- a/src/day03/mod.rs
+++ b/src/day03/mod.rs
@@ -12,11 +12,11 @@ mod tests {
 
     #[test]
     fn part03a() {
-        assert_eq!(part03a::solve(PUZZLE.to_string()), 357);
+        assert_eq!(part03a::solve(PUZZLE), 357);
     }
 
     #[test]
     fn part03b() {
-        assert_eq!(part03b::solve(PUZZLE.to_string()), 3121910778619);
+        assert_eq!(part03b::solve(PUZZLE), 3121910778619);
     }
 }
\ No newline at end of file
diff --git a/src/day03/part03a.rs b/src/day03/part03a.rs
index 72f83e1..042dd4e 100644
--- a/src/day03/part03a.rs
+++ b/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| {
diff --git a/src/day03/part03b.rs b/src/day03/part03b.rs
index 8ee8a7b..7486d8f 100644
--- a/src/day03/part03b.rs
+++ b/src/day03/part03b.rs
@@ -31,7 +31,7 @@ fn get_n_max(vec: &Vec<u8>, n: usize) -> Vec<u8> {
     max
 }
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     puzzle.lines().for_each(|battery_bank| {
diff --git a/src/day04/common.rs b/src/day04/common.rs
index 306982f..0d8f070 100644
--- a/src/day04/common.rs
+++ b/src/day04/common.rs
@@ -1,5 +1,5 @@
 
-pub fn parse_to_floor(input: String) -> Vec<Vec<u8>> {
+pub fn parse_to_floor(input: &str) -> Vec<Vec<u8>> {
     let mut rows: Vec<Vec<u8>> = Vec::with_capacity(input.len() + 2);
     rows.push(vec![0u8; input.len()]);
     rows.append(
diff --git a/src/day04/mod.rs b/src/day04/mod.rs
index 69252e6..ae4f310 100644
--- a/src/day04/mod.rs
+++ b/src/day04/mod.rs
@@ -19,11 +19,11 @@ mod tests {
 
     #[test]
     fn part04a() {
-        assert_eq!(part04a::solve(PUZZLE.to_string()), 13);
+        assert_eq!(part04a::solve(PUZZLE), 13);
     }
 
     #[test]
     fn part04b() {
-        assert_eq!(part04b::solve(PUZZLE.to_string()), 43);
+        assert_eq!(part04b::solve(PUZZLE), 43);
     }
 }
\ No newline at end of file
diff --git a/src/day04/part04a.rs b/src/day04/part04a.rs
index 4dc585f..d08a166 100644
--- a/src/day04/part04a.rs
+++ b/src/day04/part04a.rs
@@ -1,5 +1,5 @@
 use crate::day04::common::{parse_to_floor, remove_if_possible};
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     remove_if_possible(&mut parse_to_floor(puzzle)).unwrap_or_else(|| 0)
 }
diff --git a/src/day04/part04b.rs b/src/day04/part04b.rs
index 0bc78cf..5c6c3bb 100644
--- a/src/day04/part04b.rs
+++ b/src/day04/part04b.rs
@@ -1,6 +1,6 @@
 use crate::day04::common::{parse_to_floor, remove_if_possible};
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
     let mut floor = parse_to_floor(puzzle);
 
diff --git a/src/day05/mod.rs b/src/day05/mod.rs
index 7f2c7de..00ce159 100644
--- a/src/day05/mod.rs
+++ b/src/day05/mod.rs
@@ -19,11 +19,11 @@ mod tests {
 
     #[test]
     fn part05a() {
-        assert_eq!(part05a::solve(PUZZLE.to_string()), 3);
+        assert_eq!(part05a::solve(PUZZLE), 3);
     }
 
     #[test]
     fn part05b() {
-        assert_eq!(part05b::solve(PUZZLE.to_string()), 14);
+        assert_eq!(part05b::solve(PUZZLE), 14);
     }
 }
\ No newline at end of file
diff --git a/src/day05/part05a.rs b/src/day05/part05a.rs
index b23263e..24ad72e 100644
--- a/src/day05/part05a.rs
+++ b/src/day05/part05a.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let (ranges, values) = puzzle.split_once("\n\n").unwrap();
     let ranges = ranges
         .lines()
diff --git a/src/day05/part05b.rs b/src/day05/part05b.rs
index 937fdae..fc68e73 100644
--- a/src/day05/part05b.rs
+++ b/src/day05/part05b.rs
@@ -1,6 +1,6 @@
 use itertools::Itertools;
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let (ranges, _) = puzzle.split_once("\n\n").unwrap();
     let mut last_end = u64::MIN;
     ranges
diff --git a/src/day06/mod.rs b/src/day06/mod.rs
index 512dc98..f6ed64f 100644
--- a/src/day06/mod.rs
+++ b/src/day06/mod.rs
@@ -12,11 +12,11 @@ mod tests {
 
     #[test]
     fn part06a() {
-        assert_eq!(part06a::solve(PUZZLE.to_string()), 4277556);
+        assert_eq!(part06a::solve(PUZZLE), 4277556);
     }
 
     #[test]
     fn part06b() {
-        assert_eq!(part06b::solve(PUZZLE.to_string()), 3263827);
+        assert_eq!(part06b::solve(PUZZLE), 3263827);
     }
 }
diff --git a/src/day06/part06a.rs b/src/day06/part06a.rs
index 2df842a..b86c19c 100644
--- a/src/day06/part06a.rs
+++ b/src/day06/part06a.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut iters: Vec<_> = puzzle
         .lines()
         .map(|line| line.split_whitespace())
diff --git a/src/day06/part06b.rs b/src/day06/part06b.rs
index fdf48ad..9c17cd0 100644
--- a/src/day06/part06b.rs
+++ b/src/day06/part06b.rs
@@ -20,7 +20,7 @@ where
 }
 
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     let lines = puzzle
diff --git a/src/day07/mod.rs b/src/day07/mod.rs
index 1f17067..fe29829 100644
--- a/src/day07/mod.rs
+++ b/src/day07/mod.rs
@@ -24,11 +24,11 @@ mod tests {
 
     #[test]
     fn part07a() {
-        assert_eq!(part07a::solve(PUZZLE.to_string()), 21);
+        assert_eq!(part07a::solve(PUZZLE), 21);
     }
 
     #[test]
     fn part07b() {
-        assert_eq!(part07b::solve(PUZZLE.to_string()), 40);
+        assert_eq!(part07b::solve(PUZZLE), 40);
     }
 }
diff --git a/src/day07/part07a.rs b/src/day07/part07a.rs
index 6f1c59d..cd6e1a3 100644
--- a/src/day07/part07a.rs
+++ b/src/day07/part07a.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution = 0;
     let mut lines = puzzle.lines();
     let mut source = lines
diff --git a/src/day07/part07b.rs b/src/day07/part07b.rs
index fd716cd..9475788 100644
--- a/src/day07/part07b.rs
+++ b/src/day07/part07b.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution = 0;
     let mut lines = puzzle.lines();
     let mut source = lines
diff --git a/src/day08/mod.rs b/src/day08/mod.rs
index 9a609ad..8f7f3cb 100644
--- a/src/day08/mod.rs
+++ b/src/day08/mod.rs
@@ -29,12 +29,12 @@ mod tests {
     #[test]
     #[ignore]
     fn part08a() {
-        assert_eq!(part08a::solve(PUZZLE.to_string()), 40);
+        assert_eq!(part08a::solve(PUZZLE), 40);
     }
 
     #[test]
     #[ignore]
     fn part08b() {
-        assert_eq!(part08b::solve(PUZZLE.to_string()), 0);
+        assert_eq!(part08b::solve(PUZZLE), 0);
     }
 }
diff --git a/src/day08/part08a.rs b/src/day08/part08a.rs
index 986c86a..79fd1ff 100644
--- a/src/day08/part08a.rs
+++ b/src/day08/part08a.rs
@@ -1,4 +1,4 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     0 // TODO
 }
diff --git a/src/day08/part08b.rs b/src/day08/part08b.rs
index 986c86a..79fd1ff 100644
--- a/src/day08/part08b.rs
+++ b/src/day08/part08b.rs
@@ -1,4 +1,4 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     0 // TODO
 }
diff --git a/src/day09/mod.rs b/src/day09/mod.rs
index 2aa472c..f5d1b5a 100644
--- a/src/day09/mod.rs
+++ b/src/day09/mod.rs
@@ -16,12 +16,12 @@ mod tests {
 
     #[test]
     fn part09a() {
-        assert_eq!(part09a::solve(PUZZLE.to_string()), 50);
+        assert_eq!(part09a::solve(PUZZLE), 50);
     }
 
     #[test]
     #[ignore]
     fn part09b() {
-        assert_eq!(part09b::solve(PUZZLE.to_string()), 24);
+        assert_eq!(part09b::solve(PUZZLE), 24);
     }
 }
\ No newline at end of file
diff --git a/src/day09/part09a.rs b/src/day09/part09a.rs
index 5d61cf0..fcc7513 100644
--- a/src/day09/part09a.rs
+++ b/src/day09/part09a.rs
@@ -1,6 +1,6 @@
 use std::ops::Add;
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let mut solution: u64 = 0;
 
     let points = puzzle
diff --git a/src/day09/part09b.rs b/src/day09/part09b.rs
index 10fe1d8..38b3e29 100644
--- a/src/day09/part09b.rs
+++ b/src/day09/part09b.rs
@@ -1,5 +1,5 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     0 // TODO
 }
 
diff --git a/src/day10/mod.rs b/src/day10/mod.rs
index 711d482..efe91bb 100644
--- a/src/day10/mod.rs
+++ b/src/day10/mod.rs
@@ -11,12 +11,12 @@ mod tests {
 
     #[test]
     fn part10a() {
-        assert_eq!(part10a::solve(PUZZLE.to_string()), 7);
+        assert_eq!(part10a::solve(PUZZLE), 7);
     }
 
     #[test]
     #[ignore]
     fn part10b() {
-        assert_eq!(part10b::solve(PUZZLE.to_string()), 0);
+        assert_eq!(part10b::solve(PUZZLE), 0);
     }
 }
\ No newline at end of file
diff --git a/src/day10/part10a.rs b/src/day10/part10a.rs
index 2ec13c5..8153453 100644
--- a/src/day10/part10a.rs
+++ b/src/day10/part10a.rs
@@ -33,7 +33,7 @@ fn find_least_combinations<T: BitXor<Output=T> + Eq + Default + Copy>(pre_press:
     min_preferring_some(max_pressed, max_unpressed)
 }
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     puzzle
         .lines()
         .map(|line| {
diff --git a/src/day10/part10b.rs b/src/day10/part10b.rs
index 986c86a..79fd1ff 100644
--- a/src/day10/part10b.rs
+++ b/src/day10/part10b.rs
@@ -1,4 +1,4 @@
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     0 // TODO
 }
diff --git a/src/day11/mod.rs b/src/day11/mod.rs
index 7750407..187be71 100644
--- a/src/day11/mod.rs
+++ b/src/day11/mod.rs
@@ -19,12 +19,12 @@ iii: out";
 
     #[test]
     fn part11a() {
-        assert_eq!(part11a::solve(PUZZLE.to_string()), 5);
+        assert_eq!(part11a::solve(PUZZLE), 5);
     }
 
     #[test]
     #[ignore]
     fn part11b() {
-        assert_eq!(part11b::solve(PUZZLE.to_string()), 0);
+        assert_eq!(part11b::solve(PUZZLE), 0);
     }
 }
\ No newline at end of file
diff --git a/src/day11/part11a.rs b/src/day11/part11a.rs
index 7d780e0..cceba3e 100644
--- a/src/day11/part11a.rs
+++ b/src/day11/part11a.rs
@@ -1,7 +1,7 @@
 use crate::day11::common::{parse_node_graph};
 
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let node_graph  = parse_node_graph(&puzzle);
 
     node_graph.get(&"you".chars().map(|c| c as u32).reduce(|a, b| a << 8 | b).unwrap()).unwrap().borrow().find_route_to_cont("out".chars().map(|c| c as u32).reduce(|a, b| a << 8 | b).unwrap()) as u64
diff --git a/src/day11/part11b.rs b/src/day11/part11b.rs
index 0641182..e9d458b 100644
--- a/src/day11/part11b.rs
+++ b/src/day11/part11b.rs
@@ -1,7 +1,7 @@
 use crate::day11::common::{parse_node_graph};
 
 
-pub fn solve(puzzle: String) -> u64 {
+pub fn solve(puzzle: &str) -> u64 {
     let node_graph  = parse_node_graph(&puzzle);
 
     node_graph.get(&"you".chars().map(|c| c as u32).reduce(|a, b| a << 8 | b).unwrap()).unwrap().borrow().find_route_to_cont("out".chars().map(|c| c as u32).reduce(|a, b| a << 8 | b).unwrap()) as u64
diff --git a/src/main.rs b/src/main.rs
index f0fca35..01e8b81 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -26,7 +26,7 @@ fn main() {
     file.write_all(b"# Advent of Code 2025\n```bash\n")
         .expect("Cannot write to file");
 
-    let exercises: Vec<(&str, fn(String) -> u64, &str)> = vec![
+    let exercises: Vec<(&str, fn(&str) -> u64, &str)> = vec![
         ("day01:A", day01::part01a::solve, "puzzles/input01.txt"),
         ("day01:B", day01::part01a::solve, "puzzles/input01.txt"),
         ("day02:A", day02::part02a::solve, "puzzles/input02.txt"),
@@ -58,7 +58,7 @@ fn main() {
         let solution = format!(
             "{:7} => {:15}  ({:6}us)\n",
             day,
-            func(file_content),
+            func(&file_content),
             day_start.elapsed().as_micros()
         );
         print!("{}", solution);