Add 2020 day 6

2020/day6/day6.js

@@ -0,0 +1,34 @@
+#!/bin/node
+
+const fs = require('fs');
+
+fs.readFile('input.txt', (err, data) => {
+    const groups = data.toString()
+        .split('\n\n')
+        .map(group => group.split('\n')
+            .filter(person => person.length > 0));
+
+    let q1 = 0;
+    let q2 = 0;
+    for (const group of groups) {
+        let q1Questions = [];
+        let q2Questions = [];
+
+        for (const person of group) {
+            for (const question of person) {
+                if (q1Questions.indexOf(question) < 0) {
+                    q1Questions.push(question);
+
+                    if (group.every(person => person.indexOf(question) >= 0)) {
+                        q2Questions.push(question);
+                    }
+                }
+            }
+        }
+
+        q1 += q1Questions.length;
+        q2 += q2Questions.length;
+    }
+
+    console.log(q1, q2);
+});