Top K Frequent Elements solution

Author: kim-young

top-k-frequent-elements/kimyoung.js

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+var topKFrequent = function (nums, k) {
+  let obj = {};
+  for (const num of nums) {
+    obj[num] ? obj[num]++ : (obj[num] = 1);
+  }
+  let sorted = Object.entries(obj).sort((a, b) => b[1] - a[1]);
+  let result = [];
+  for (let i = 0; i < k; i++) {
+    result.push(sorted[i][0]);
+  }
+  return result;
+};
+
+// test cases
+console.log(topKFrequent([1, 1, 1, 2, 2, 3], 2)); // [1, 2]
+console.log(topKFrequent([1], 1)); // [1]
+
+// space - O(n) - mapping the object in [key, freq]
+// time - O(nlogn) - sorting the mapped objects in the order of frequency