Leetcode——每日一题T14. 最长公共前缀（zip函数法）

法一：正向法（增加字符串）

class Solution:
def longestCommonPrefix(self, strs: List[str]) -> str:
    if strs ==[]:
        return ''
    result = ''
    a = strs[0]
    for temp in strs:
        if len(temp) < len(a):
            a = temp
    for i in range(len(a)):
        for j in range(len(strs)):
            if a[i] != strs[j][i]:
                return result
        result += a[i]
    return result

法二：逆向法（缩短字符串）

class Solution:
def longestCommonPrefix(self, strs: List[str]) -> str:
    if strs ==[]:
        return ''
    a = strs[0]
    for i in range(len(strs)):
        while strs[i].find(a) != 0:
            a = a[:-1]
    return a

法三：zip函数法

class Solution:
def longestCommonPrefix(self, strs: List[str]) -> str:
    if strs ==[]:
        return ''
    result = ''
    for i in zip(*strs):
        if len(set(i)) == 1:
            result += i[0]
        else:
            break
    return result