Easy, Array/String

确定一个string列里各个string的最长共同前缀

各个string并列后从左到右对比，如果同一位值的字符相同，加入响应，否则返回。这里到了set()来确定是否相同。

class Solution(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        pre = ''
        i = 0
        while True:
            str_lens = [len(str) for str in strs]
            if all(len>i for len in str_lens):
                com = set([str[i] for str in strs])
                if len(com) == 1:
                    pre += list(com)[0]
                else:
                    break
            else:
                break
            i += 1
        return pre