【leetcode刷题】20T9-最长公共前缀

示例 1:
输入: ["flower","flow","flight"]
输出: "fl"

示例 2:
输入: ["dog","racecar","car"]
输出: ""
解释: 输入不存在公共前缀。

class Solution(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        if len(strs) == 0:
            return ''
        i = 0
        flag = True
        while i < len(strs[0]):
            for si in strs:
                # 比较每个字符是否一样
                if i >= len(si) or si[i] != strs[0][i]:
                    flag = False
                    break
            if not flag:
                break
            i += 1
        return strs[0][:i]