public class Solution
extends Object
347 - Top K Frequent Elements\.
Medium
Given an integer array `nums` and an integer `k`, return _the_ `k` _most frequent elements_. You may return the answer in **any order**.
**Example 1:**
**Input:** nums = [1,1,1,2,2,3], k = 2
**Output:** [1,2]
**Example 2:**
**Input:** nums = [1], k = 1
**Output:** [1]
**Constraints:**
* 1 <= nums.length <= 105
* `k` is in the range `[1, the number of unique elements in the array]`.
* It is **guaranteed** that the answer is **unique**.
**Follow up:** Your algorithm's time complexity must be better than `O(n log n)`, where n is the array's size.