python3 最长公共前缀

给定一个大小为 n 的字符串数组 strs ，其中包含n个字符串 , 编写一个函数来查找字符串数组中的最长公共前缀，返回这个公共前缀。

import random
import re
 
class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        if len(strs) == 0:
            return ""
        elif "" in strs:
            return ""
        m = min([len(i) for i in strs])
        smin = []
        for j in strs:
            if len(j) == m:
                smin.append(j)
        tar = random.choice(smin)
 
        for i in range(m, 0, -1):
            new = tar[:i]
            c = 0
            for k in strs:
                pattern = re.match(new, k)
                if pattern:
                    c += 1
                else:
                    break
            if c == len(strs):
                return new
                break
            elif len(new) == 1 and c == 0:
                return ""