【week 8.2】LeetCode 14. Longest Common Prefix

1.题目

Write a function to find the longest common prefix string amongst an array of strings.

If there is no common prefix, return an empty string "".

Example 1:

Input: ["flower","flow","flight"]
Output: "fl"

Example 2:

Input: ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.

Note:

All given inputs are in lowercase letters a-z.

2.解析

题意是寻找数组中字符串中的最大公共子串，既然是公共子串，所以数组中每一个字符串都有该子串。因此先默认第一个字符串为公共子串，然后和后面的字符串依次对比，最小的那个就是；

3.代码

扫描二维码关注公众号，回复： 1681539 查看本文章

class Solution:  
    # @param {string[]} strs  
    # @return {string}  
    def longestCommonPrefix(self, strs):  
        if len(strs)==0:return ""  
        str=strs[0]  
        Min=len(str)  
        for i in range(1,len(strs)):  
            j=0;p=strs[i]  
            while j<Min and j<len(p) and p[j]==str[j]:j+=1  
            Min = Min if Min<j else j  
        return str[:Min]