2022 Day 6

2022/src/bin/day06.rs

@@ -0,0 +1,38 @@
+use std::collections::HashSet;
+
+const INPUT: &str = include_str!("../../input/day06.txt");
+
+fn main() {
+    println!("{}", part1(INPUT));
+    println!("{}", part2(INPUT));
+}
+
+fn part1(input: &str) -> usize {
+    let sig: Vec<char> = input.trim().chars().collect();
+
+    for i in 0..(sig.len()) {
+        let buf = &sig[i..(i + 4)];
+        if all_different(buf) {
+            return i + 4;
+        }
+    }
+
+    0
+}
+
+fn all_different(c: &[char]) -> bool {
+    c.iter().cloned().collect::<HashSet<char>>().len() == c.len()
+}
+
+fn part2(input: &str) -> usize {
+    let sig: Vec<char> = input.trim().chars().collect();
+
+    for i in 0..(sig.len()) {
+        let buf = &sig[i..(i + 14)];
+        if all_different(buf) {
+            return i + 14;
+        }
+    }
+
+    0
+}