diff --git a/src/day03.rs b/src/day03.rs
index 6c82367..28b0cce 100644
--- a/src/day03.rs
+++ b/src/day03.rs
@@ -1,5 +1,7 @@
+use std::collections::HashSet;
 use crate::utils;
 
+
 pub fn execute_task01(content: &str) {
     let sum = solve_task01(content);
 
@@ -14,89 +16,40 @@ pub fn execute_task02(content: &str) {
 
 fn solve_task01(content: &str) -> i32 {
     let vector = utils::convert_to_string_slice(&content);
-    let rucksack_compartments: Vec<(Vec<char>, Vec<char>)> = vector.iter().map(|line| split_rucksack_in_two_compartments(line)).collect();
 
-    let duplicates: Vec<char> = rucksack_compartments.iter()
-    .flat_map(|(vec1, vec2)| vec1.iter()
-    .copied()
-    .flat_map(|entry| vec2.iter().copied().map(move |b| (entry, b)))
-    .filter(|(a, b)| a == b)
-    .map(|(a, _)| a))
-    .collect();
-
-    duplicates.iter().copied().map(|c| convert_char_to_prio(&c)).sum()
+    vector.into_iter()
+        .map(|x| [&x[..x.len()/2], &x[x.len()/2..]]
+            .into_iter()
+            .map(|x| x.chars().collect::<HashSet<_>>())
+            .reduce(|acc, x| &acc & &x).unwrap())
+        .map(|x| *x.iter().next().unwrap())
+        .map(|c| convert_char_to_prio(c) as i32)
+        .sum()
 }
 
 fn solve_task02(content: &str) -> i32 {
     let vector = utils::convert_to_string_slice(&content);
-    let compartments: Vec<Vec<char>> = vector.iter().map(|line| split_rucksack_in_items(line)).collect();
-    let mut duplicates: Vec<char> = vec![];
 
-    for i in 0..(compartments.len()/3) {
-        let first_index = i * 3 + 0;
-        let second_index = i * 3 + 1;
-        let third_index = i * 3 + 2;
-
-        let first_vec = compartments.get(first_index).expect("ERR");
-        let second_vec = compartments.get(second_index).expect("ERR");
-        let third_vec = compartments.get(third_index).expect("ERR");
-
-        let mut dups: Vec<char> = first_vec.into_iter()
-        .copied()
-        .flat_map(|val1| second_vec.into_iter()
-        .copied()
-        .flat_map(move |val2| third_vec.into_iter().copied().map(move |val3| (val1, val2, val3))))
-        .filter(|(a, b, c)| a == b && b == c)
-        .map(|(a, _, _)| a)
-        .collect();
-
-        duplicates.append(&mut dups)
-    }
-
-    duplicates.iter().copied().map(|c| convert_char_to_prio(&c)).sum()
+    vector.chunks(3).into_iter()
+        .map(|content| [content[0], content[1], content[2]].into_iter()
+            .map(|x| x.chars().collect::<HashSet<_>>())
+            .reduce(|acc, x| &acc & &x).unwrap())
+        .map(|x| *x.iter().next().unwrap())
+        .map(|c| convert_char_to_prio(c) as i32)
+        .sum()
 }
 
-fn split_rucksack_in_two_compartments(rucksack_content: &str) -> (Vec<char>, Vec<char>) {
-    let first_compartment: &str = &rucksack_content[..rucksack_content.len()/2];
-    let second_compartment: &str = &rucksack_content[rucksack_content.len()/2..];
-
-    let mut first_compartment_vec: Vec<char> = first_compartment.chars().map(|c| c).collect();
-    let mut second_compartment_vec: Vec<char> = second_compartment.chars().map(|c| c).collect();
-
-    first_compartment_vec.sort();
-    first_compartment_vec.dedup();
-    second_compartment_vec.sort();
-    second_compartment_vec.dedup();
-
-    return ( first_compartment_vec, second_compartment_vec);
-}
-
-fn split_rucksack_in_items(rucksack_content: &str) -> Vec<char> {
-    let mut vec: Vec<char> = rucksack_content.chars().map(|c| c).collect();
-
-    vec.sort();
-    vec.dedup();
-
-    return vec;
-}
-
-pub fn convert_char_to_prio(c: &char) -> i32 {
-    let c_code = c.clone() as u8;
-
-    if 65 <= c_code && c_code < 91 {
-        return (c_code - 64 + 26) as i32;
+pub fn convert_char_to_prio(c: char) -> u8 {
+    let c = c as u8;
+    match c {
+        b'a'..=b'z' => c - b'a' + 1,
+        b'A'..=b'Z' => c - b'A' + 27,
+        _ => unreachable!(),
     }
-
-    if 97 <= c_code && c_code < 123 {
-        return (c_code - 96) as i32;
-    }
-
-    panic!("never should called");
 }
 
 #[cfg(test)]
 mod test {
-
     const EXAMPLE01: &'static str = include_str!("input/day03/example01");