[Leetcode] Top K Frequent Elements

Use partial sorting to outperform O(nlogn).

Description

Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.

Examples

Example 1:

Input: nums = [1,1,1,2,2,3], k = 2
Output: [1,2]

Example 2:

Input: nums = [1], k = 1
Output: [1]

Solution

Heapq in python keeps the smallest being the root. Therefore, by popping root when already pushing k elements, only top k would be kept. Notice that pop() is O(log n), fast enought to pass the requirment .

• code

ref:

leetcode 347. Top K Frequent Elements (Python)

【LeetCode】347. Top K Frequent Elements 解题报告（Python & C++）_负雪明烛-CSDN博客