2025-08-22 15:39:40 +0000 UTC

class Solution:
    def countKeyChanges(self, s: str) -> int:
        res = 0
        for i in range(1, len(s)):
            cur, prev = ord(s[i]), ord(s[i - 1])
            if cur < 97:
                cur += 32
            if prev < 97:
                prev += 32
            if cur != prev:
                res += 1
        return res