From 62d5e5b6c0e0936bf8962869fd01e1df0790466b Mon Sep 17 00:00:00 2001
From: Antoine Martin <antoine97.martin@gmail.com>
Date: Sun, 6 Dec 2020 13:02:21 +0100
Subject: [PATCH] 2020: day06: cleanup

---
 aoc2020/src/day06.rs | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/aoc2020/src/day06.rs b/aoc2020/src/day06.rs
index fc58c5b..c7db5a5 100644
--- a/aoc2020/src/day06.rs
+++ b/aoc2020/src/day06.rs
@@ -41,12 +41,7 @@ fn part1(input: &str) -> aoc::Result<usize> {
 
     Ok(groups
         .iter()
-        .map(|group| {
-            group.answers.iter().fold(HashSet::new(), |set, answers| {
-                set.union(answers).copied().collect()
-            })
-        })
-        .map(|set| set.len())
+        .map(|group| group.unique_positive_answers().len())
         .sum())
 }
 
@@ -55,16 +50,7 @@ fn part2(input: &str) -> aoc::Result<usize> {
 
     Ok(groups
         .iter()
-        .map(|group| {
-            group
-                .answers
-                .iter()
-                .skip(1)
-                .fold(group.answers[0].clone(), |set, answers| {
-                    set.intersection(answers).copied().collect()
-                })
-        })
-        .map(|set| set.len())
+        .map(|group| group.common_positive_answers().len())
         .sum())
 }
 
@@ -72,6 +58,23 @@ struct Group {
     answers: Vec<HashSet<u8>>,
 }
 
+impl Group {
+    fn unique_positive_answers(&self) -> HashSet<u8> {
+        self.answers.iter().fold(HashSet::new(), |set, answers| {
+            set.union(answers).copied().collect()
+        })
+    }
+
+    fn common_positive_answers(&self) -> HashSet<u8> {
+        self.answers
+            .iter()
+            .skip(1)
+            .fold(self.answers[0].clone(), |set, answers| {
+                set.intersection(answers).copied().collect()
+            })
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;