Solution
from typing import List
class Solution:
def validUtf8(self, data: List[int]) -> bool:
cnt = 0
for v in data:
if cnt > 0:
# 后续字节必须以 10 开头
if v >> 6 != 0b10:
return False
cnt -= 1
elif v >> 7 == 0:
# 1字节字符：0xxxxxxx
cnt = 0
elif v >> 5 == 0b110:
# 2字节：110xxxxx
cnt = 1
elif v >> 4 == 0b1110:
# 3字节：1110xxxx
cnt = 2
elif v >> 3 == 0b11110:
# 4字节：11110xxx
cnt = 3
else:
# 非法开头 11111xxx 或者 10xxxxxx作为起始
return False
return cnt == 0
# 本地测试
if __name__ == "__main__":
sol = Solution()
print(sol.validUtf8([197,130,1])) # True
print(sol.validUtf8([235,140,4])) # False
print(sol.validUtf8([250,145,145,145,145])) #True