Added GroupAnagrams

LeetcodeProblems/GroupAnagrams.js

@@ -0,0 +1,54 @@
+/*
+https://leetcode.com/problems/group-anagrams/description/
+
+Given an array of strings, group anagrams together.
+
+Example:
+
+Input: ["eat", "tea", "tan", "ate", "nat", "bat"],
+Output:
+[
+  ["ate","eat","tea"],
+  ["nat","tan"],
+  ["bat"]
+]
+Note:
+
+All inputs will be in lowercase.
+The order of your output does not matter.
+*/
+
+var groupAnagrams = function(strs) {
+  var ret = [];
+  var hashMap = {};
+  for(var i = 0; i < strs.length; i++) {
+      const elem = strs[i];
+      const elemSorted = sortString(strs[i]);
+
+      if(hashMap[elemSorted]) {
+          hashMap[elemSorted].push(elem);
+      } else {
+          hashMap[elemSorted] = [elem];
+      }
+  }
+
+  for(key in hashMap) {
+    ret.push(hashMap[key]);
+  }
+
+  return ret;
+};
+
+var sortString = function(str) {
+  if(str.length === 0) {
+      return str;
+  }
+
+  return str.split("").sort().join("");
+}
+
+var main = function() {
+  console.log(groupAnagrams(["eat", "tea", "tan", "ate", "nat", "bat"]));
+}
+
+module.exports.main = main;