leetcode-168周赛-1297-子串的最大出现次数

题目描述：

自己的提交：

class Solution:
    def maxFreq(self, s: str, maxLetters: int, minSize: int, maxSize: int) -> int:
        c = collections.Counter()
        for i in range(len(s)-minSize+1):
            if len(set(s[i:i+minSize])) <= maxLetters:
                c[s[i:i+minSize]] += 1
        if not c:
            return 0
        else:
            return max(v for i,v in c.items())

优化：

class Solution:
    def maxFreq(self, s: str, maxLetters: int, minSize: int, maxSize: int) -> int:
        c = collections.Counter()
        for i in range(len(s)-minSize+1):
            if len(set(s[i:i+minSize])) <= maxLetters:
                c[s[i:i+minSize]] += 1
        return max(c.values(),default = 0)