Add solution #884

Author: JoshCrozier

README.md

@@ -56,6 +56,7 @@
 831|[Masking Personal Information](./0831-masking-personal-information.js)|Medium|
 844|[Backspace String Compare](./0844-backspace-string-compare.js)|Easy|
 867|[Transpose Matrix](./0867-transpose-matrix.js)|Easy|
+884|[Uncommon Words from Two Sentences](./0884-uncommon-words-from-two-sentences.js)|Easy|
 890|[Find and Replace Pattern](./0890-find-and-replace-pattern.js)|Medium|
 916|[Word Subsets](./0916-word-subsets.js)|Medium|
 925|[Long Pressed Name](./0925-long-pressed-name.js)|Easy|

solutions/0884-uncommon-words-from-two-sentences.js

@@ -0,0 +1,26 @@
+/**
+ * 884. Uncommon Words from Two Sentences
+ * https://leetcode.com/problems/uncommon-words-from-two-sentences/submissions/
+ * Difficulty: Easy
+ *
+ * A sentence is a string of single-space separated words where each word consists
+ * only of lowercase letters.
+ *
+ * A word is uncommon if it appears exactly once in one of the sentences, and does
+ * not appear in the other sentence.
+ *
+ * Given two sentences s1 and s2, return a list of all the uncommon words. You may
+ * return the answer in any order.
+ */
+
+/**
+ * @param {string} s1
+ * @param {string} s2
+ * @return {string[]}
+ */
+var uncommonFromSentences = function(s1, s2) {
+  const map = new Map();
+
+  (s1 + ' ' + s2).split(/\s+/).forEach(s => map.set(s, (map.get(s) || 0) + 1));
+  return [...map].reduce((a, [k, c]) => c === 1 ? [...a, k] : a, []);
+};