Day 6 - add 2nd solving strategy

src/days/d06.rs

@@ -18,6 +18,8 @@ pub fn solve() {
     println!("Result 2: {}", res);
 }
 
+
+
 // Finds 1st occurence of l unique characters in chars and returns
 // the index of the last of them or -1
 fn find_marker(l: usize, chars: &Vec<char>) -> i32 {
@@ -34,3 +36,13 @@ fn find_marker(l: usize, chars: &Vec<char>) -> i32 {
 
     -1
 }
+
+fn _find_marker_v2(l: usize, chars: &Vec<char>) -> usize {
+    chars.iter()
+        .filter(|c| **c != '\n')
+        .collect::<Vec<&char>>()
+        .windows(l)
+        .position(|window| window.iter().collect::<HashSet<_>>().len() == l)
+        .map(|pos| pos+l)
+        .unwrap()
+}