From 0494dee19d95d1da0936691f4c60d415889fb5b7 Mon Sep 17 00:00:00 2001
From: Johannes <jschaef@mail.uni-paderborn.de>
Date: Sat, 1 Dec 2018 17:54:30 +0100
Subject: [PATCH] day01-2 tuple

---
 src/tasks/day01.rs | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/src/tasks/day01.rs b/src/tasks/day01.rs
index ec7e19e..f70747c 100644
--- a/src/tasks/day01.rs
+++ b/src/tasks/day01.rs
@@ -13,21 +13,18 @@ pub fn task1() {
 pub fn task2() {
     let contents = utils::read_file("input/day01.txt");
 
-    let mut seen: HashSet<i32> = HashSet::new();
-    seen.insert(0);
-    let start_state = (std::cell::RefCell::new(seen), std::cell::RefCell::new(0));
+    let seen: HashSet<i32> = vec![0].into_iter().collect();
+    let start_state = (seen, 0);
     let final_state = contents
         .lines()
         .map(|line| line.parse::<i32>().unwrap())
         .cycle()
-        .scan(&start_state, |(hash_set, current_freq), freq_change| {
-            *current_freq.borrow_mut() += freq_change;
-            if hash_set.borrow_mut().contains(&current_freq.borrow()) {
-                Some((current_freq.borrow(), true))
+        .scan(start_state, |state, freq_change| {
+            state.1 += freq_change;
+            if state.0.insert(state.1) {
+                Some((state.1, false))
             } else {
-                let value: i32 = *current_freq.borrow_mut();
-                hash_set.borrow_mut().insert(value);
-                Some((current_freq.borrow(), false))
+                Some((state.1, true))
             }
         }).find(|state| state.1);