add top-k-frequent-elements solution

Author: nakjun12

top-k-frequent-elements/nakjun12.ts

@@ -0,0 +1,11 @@
+function topKFrequent(nums: number[], k: number): number[] {
+  const frequency = nums.reduce(
+    (acc, n) => acc.set(n, (acc.get(n) ?? 0) + 1),
+    new Map<number, number>()
+  );
+
+  return Array.from(frequency)
+    .sort((a, b) => b[1] - a[1])
+    .slice(0, k)
+    .map((item) => item[0]);
+}