Mid/SeniorArrayBucket SortCountingDivide and ConquerHash TableHeap (Priority Queue)QuickselectSorting
Top K Frequent Elements
Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.
Follow up: Your algorithm's time complexity must be better than O(n log n), where n is the array's size.
Example 1
Input
nums = [1,1,1,2,2,3], k = 2Output
[1,2]The two most frequent elements are 1 and 2.
Example 2
Input
nums = [1], k = 1Output
[1]The only element is 1, so it is the most frequent element.
Constraints
- 1 <= nums.length <= 10^5
- -10^4 <= nums[i] <= 10^4
- k is in the range [1, the number of unique elements in the array].
- It is guaranteed that the answer is unique.