From 27772c83b7e95321c1fdbd9a6485da9c2bf40ef5 Mon Sep 17 00:00:00 2001
From: Jeremy Kaplan <jdkaplan@metagram.net>
Date: Mon, 5 Dec 2022 21:08:57 -0800
Subject: [PATCH] 2022 Day 6

---
 2022/src/bin/day06.rs | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 2022/src/bin/day06.rs

diff --git a/2022/src/bin/day06.rs b/2022/src/bin/day06.rs
new file mode 100644
index 0000000..4582c78
--- /dev/null
+++ b/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
+}