由于今天做了周赛，每日一题就简单点直接暴力哈希

class Solution:
    def findRepeatedDnaSequences(self, s: str) -> List[str]:
        d = defaultdict(int)
        ans = []
        for i in range(len(s) - 9):
            t = s[i: i + 10]
            d[t] += 1
            if d[t] == 2:
                ans.append(t)
        return ans