[TASK] Solved day 6

input/day6_example.txt

@@ -0,0 +1,15 @@
+abc
+
+a
+b
+c
+
+ab
+ac
+
+a
+a
+a
+a
+
+b

src/day6.rs

@@ -0,0 +1,58 @@
+// use super::util;
+use std::fs;
+
+pub fn solve() {
+
+    let raw_input = fs::read_to_string("input/day6.txt").expect("Couldn't read file!");
+    let groups = raw_input
+        .split("\r\n\r\n")
+        .map(|g| g.lines().map(|p| String::from(p)).collect::<Vec<_>>())
+        .collect::<Vec<_>>();
+
+    let part1: usize = groups.iter()
+        .map(|g| count_answers(&g))
+        .sum();
+
+    println!("Day 6 Part 1: {}", part1);
+
+    let part2: u32 = groups.iter()
+        .map(|g| count_equal_answers(&g))
+        .sum();
+
+    println!("Day 6 Part 2: {}", part2);
+}
+
+fn count_answers(group: &Vec<String>) -> usize {
+
+    let mut answers: Vec<char> = group.join("").chars().collect::<Vec<_>>();
+    answers.sort();
+    answers.dedup();
+
+    return answers.len();
+}
+
+fn count_equal_answers(group: &Vec<String>) -> u32 {
+
+    let mut it = group.iter();
+    let mut answers: u32 = to_flags(it.next().unwrap());
+
+    loop {
+        let cur = it.next();
+        if cur.is_some() {
+            answers &= to_flags(cur.unwrap())
+        } else {
+            break;
+        }
+    }
+
+    return answers.count_ones();
+}
+
+fn to_flags(answers: &String) -> u32 {
+
+    let mut res = 0;
+    let a = 'a' as u32;
+    answers.chars().for_each(|c| res |= 1 << ((c as u32) - a));
+    return res;
+
+}

src/main.rs

@@ -7,6 +7,7 @@ mod day2;
 mod day3;
 mod day4;
 mod day5;
+mod day6;
 
 fn main() {
 
@@ -22,6 +23,7 @@ fn main() {
             3 => day3::solve(),
             4 => day4::solve(),
             5 => day5::solve(),
+            6 => day6::solve(),
             _ => println!("This day is not yet implemented")
         }
     } else {
@@ -31,6 +33,7 @@ fn main() {
         day3::solve();
         day4::solve();
         day5::solve();
+        day6::solve();
     }
 
     println!("Execution took {} μs", now.elapsed().as_micros());