2025-08-19 06:58:54 +0000 UTC

class Solution:
    def repeatedCharacter(self, s: str) -> str:
        freqs = [0] * 26
        for char in s:
            idx = ord(char) - 97
            freq = freqs[idx] + 1
            if freq == 2:
                return char
            freqs[idx] = freq
        raise Exception