def longestCommonPrefix(self, strs):    """    :type strs: List[str]    :rtype: str    """    if not strs:      return ""    first_str = strs[0]    other_strs = strs[1:]    prefix = ""    for i in first_str:      prefix += i      for s in other_strs:        if not s.startswith(prefix):          return prefix[:-1]    return prefix

class Solution(object):  def longestCommonPrefix(self, strs):    """    :type strs: List[str]    :rtype: str    """    if not strs:       return ""    if len(strs) == 1:      return strs[0]    prefix = strs[0]    for i in range(len(strs)-1):      if not prefix:        return ""      prefix = self.getCommonPrefix(prefix,strs[i+1])    return prefix  #先定義一個(gè)函數(shù)求出兩個(gè)字符串的最長(zhǎng)公共前綴  def getCommonPrefix(self,str1,str2):    if not str1 or not str2:      return ""    prefix = ""    for s in str1:      prefix += s      if not str2.startswith(prefix):        return prefix[:-1]    return prefix