6.15

https://leetcode-cn.com/problems/longest-common-prefix/每日一题

class Solution(object):
    def longestCommonPrefix(self, strs):
        n = len(strs)
        ans = ''
        j = 0
        if n == 0:
            return ans
        if n == 1:
            return strs[0]
        while 1:
            for i in range(1,n):
                if len(strs[i-1]) <= j or len(strs[i]) <= j :
                    return ans
                if strs[i-1][j] != strs[i][j]:
                    return ans
            ans = strs[0][:j+1]
            j = j+1