14 Longest Common Prefix

两种思路： 第一种 vertical match, 第二种是 horizontal match

class Solution(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        if len(strs) == 0:
            return ""
        for i in range(len(strs[0])):
            c = strs[0][i]
            for j in range(1, len(strs)):
                if i == len(strs[j]) or strs[j][i] != c:
                    return strs[0][:i]
        return strs[0]