from typing import List
class Solution:
def longestCommonPrefix(self, strs: List[str]) -> str:
if not strs:
return ""
取第一个字符串作为初始公共前缀
prefix = strs[0]
for s in strs[1:]:
while s.find(prefix)!= 0:
如果当前字符串不以prefix开头，截掉prefix最后一个字符继续尝试
prefix = prefix[:-1]
if not prefix:
return ""
return prefix
