From 30c04711c9371d957af426d8b14100ef6d9f0255 Mon Sep 17 00:00:00 2001
From: Alice Gaudon <alice@gaudon.pro>
Date: Sun, 6 Dec 2020 14:10:21 +0100
Subject: [PATCH] Day 6: optimize q2 by starting from q1 answer

---
 2020/day6/day6.js | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/2020/day6/day6.js b/2020/day6/day6.js
index 8d25017..162dd2c 100755
--- a/2020/day6/day6.js
+++ b/2020/day6/day6.js
@@ -19,13 +19,11 @@ fs.readFile('input.txt', (err, data) => {
                 if (q1Questions.indexOf(question) < 0) {
                     q1Questions.push(question);
                 }
-
-                if (q2Questions.indexOf(question) < 0 && group.every(person => person.indexOf(question) >= 0)) {
-                    q2Questions.push(question);
-                }
             }
         }
 
+        q2Questions = q1Questions.filter(question => group.every(person => person.indexOf(question) >= 0));
+
         q1 += q1Questions.length;
         q2 += q2Questions.length;
     }