add: topKFrequentElements solution

Author: Cyjin-jani

top-k-frequent-elements/Cyjin-jani.js

@@ -0,0 +1,16 @@
+const topKFrequent = function (nums, k) {
+  const tempArr = Array.from({ length: nums.length }, () => []);
+  const obj = {};
+
+  for (let num of nums) {
+    obj[num] = (obj[num] || 0) + 1;
+  }
+
+  for (let key in obj) {
+    const val = obj[key] - 1;
+    tempArr[val].push(+key);
+  }
+
+  const answer = tempArr.flat();
+  return answer.slice(-k);
+};