1888. Minimum Number of Flips to Make the Binary String Alternating

class Solution:
    def minFlips(self, s: str) -> int:
        n = len(s)
        target = "01"
        cnt = sum(c != target[i & 1] for i, c in enumerate(s))
        res = min(cnt, n - cnt)
        for i in range(n):
            cnt -= s[i] != target[i & 1]
            cnt += s[i] != target[(i + n) & 1]
            res = min(res, cnt, n - cnt)
        return res