From 00e4852f096c5a6d5647c1d688cdcd93268907b7 Mon Sep 17 00:00:00 2001
From: Grzegorz Kucmierz <gkucmierz@gmail.com>
Date: Fri, 15 Nov 2019 16:37:32 +0100
Subject: [PATCH] Anagram difference

---
 anagram-difference/index.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 anagram-difference/index.js

diff --git a/anagram-difference/index.js b/anagram-difference/index.js
new file mode 100644
index 0000000..065f4d8
--- /dev/null
+++ b/anagram-difference/index.js
@@ -0,0 +1,12 @@
+// https://www.codewars.com/kata/anagram-difference
+
+function anagramDifference([...a1], [...a2]) {
+  return a1.length + a2.length - intersection(a1, a2).length * 2;
+}
+
+// https://gist.github.com/gkucmierz/8ee04544fa842411f7553ef66ac2fcf0
+const intersection = (a1, a2) => {
+  const cnt = new Map();
+  a2.map(el => cnt[el] = el in cnt ? cnt[el] + 1 : 1);
+  return a1.filter(el => el in cnt && 0 < cnt[el]--);
+};