days 5 + 6

day06/src/main.rs

@@ -0,0 +1,17 @@
+use rustc_hash::FxHashSet;
+const PACKET_WINDOW_SIZE: usize = 4;
+const MESSAGE_WINDOW_SIZE: usize = 14;
+
+fn main() {
+    let s = std::fs::read_to_string("/dev/stdin").unwrap();
+    println!("P1: {}, P2: {}", find_index(&s, PACKET_WINDOW_SIZE), find_index(&s, MESSAGE_WINDOW_SIZE));
+}
+
+fn find_index(s: &str, window_size: usize) -> usize {
+    for (count, window) in s.chars().collect::<Vec<char>>().windows(window_size).enumerate(){
+        if FxHashSet::from_iter(window).len() == window_size {
+            return count + window_size;
+        }
+    }
+    0
+}