https://leetcode.com/problems/top-k-frequent-words/

max_heap.py

from collections import Counter
from heapq import heappush, heappop, heappushpop

class Item(object):
    def __init__(self, word, freq):
        self.word = word
        self.freq = freq
        
    def __lt__(self, other):
        if self.freq == other.freq:
            return self.word > other.word # lower alpha order
        return self.freq < other.freq # higher freq

class Solution:
    def topKFrequent(self, words: List[str], k: int) -> List[str]:
        c = Counter(words)
        heap = []
        heapify(heap)
        
        for key in c:
            item = Item(key, c[key])
            if len(heap) < k:
                heappush(heap, item)
            elif item > heap[0]: 
                heappop(heap)
                heappush(heap, item)
                
        res = []
        
        for _ in range(k):
            res.append(heappop(heap).word)
            
        return res[::-1]