[leetcode 14] 最长公共前缀

写一个函数可以查找字符串中的最长公共字符。

示例：

输入：["flower","flow","flight"]

输出："fl"

输入：["dog","racecar","car"]

输出：" " （不存在公共的字符串）

代码：

class Solution:
    def longestCommonPrefix(self,strs):
          """
            :type strs: List[str]
            :rtype:  str
          """

            if len(strs) == 0:
              return ""
            
              prefix=""
              length=1

             while length <= min([len(s) for s in strs]):
                   for i in range(1,len(strs)):
                        if strs[i][:length] != strs[i-1][:length]:
                            return prefix
                   result = strs[0][:length]
                   length +=1
             return prefix