From c6f3bfe8f68d2e71d10d422df281682cfba60415 Mon Sep 17 00:00:00 2001
From: June McEnroe <june@causal.agency>
Date: Fri, 1 Dec 2017 00:55:04 -0500
Subject: Day 1, part 2

---
 2017/src/bin/day01.rs | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/2017/src/bin/day01.rs b/2017/src/bin/day01.rs
index ee81d15..70ca5a6 100644
--- a/2017/src/bin/day01.rs
+++ b/2017/src/bin/day01.rs
@@ -1,10 +1,10 @@
 use std::io::{self, Read};
 
-fn solve(input: &str) -> u32 {
+fn solve(input: &str, skip: usize) -> u32 {
     let mut sum = 0;
 
     let chars = input.chars();
-    let nexts = input.chars().cycle().skip(1);
+    let nexts = input.chars().cycle().skip(skip);
 
     for (a, b) in chars.zip(nexts) {
         if a == b {
@@ -15,17 +15,31 @@ fn solve(input: &str) -> u32 {
     sum
 }
 
+fn solve2(input: &str) -> u32 {
+    solve(input, input.len() / 2)
+}
+
 fn main() {
     let mut input = String::new();
     io::stdin().read_to_string(&mut input).unwrap();
 
-    println!("Part 1: {}", solve(input.trim()));
+    println!("Part 1: {}", solve(input.trim(), 1));
+    println!("Part 2: {}", solve2(input.trim()));
 }
 
 #[test]
 fn part1() {
-    assert_eq!(3, solve("1122"));
-    assert_eq!(4, solve("1111"));
-    assert_eq!(0, solve("1234"));
-    assert_eq!(9, solve("91212129"));
+    assert_eq!(3, solve("1122", 1));
+    assert_eq!(4, solve("1111", 1));
+    assert_eq!(0, solve("1234", 1));
+    assert_eq!(9, solve("91212129", 1));
+}
+
+#[test]
+fn part2() {
+    assert_eq!(6, solve2("1212"));
+    assert_eq!(0, solve2("1221"));
+    assert_eq!(4, solve2("123425"));
+    assert_eq!(12, solve2("123123"));
+    assert_eq!(4, solve2("12131415"));
 }
-- 
cgit 1.4.1