[leetcode] 14. Longest Common Prefix

 

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: strs = ["flower","flow","flight"]

Output: "fl"

 

Example 2:

Input: strs = ["dog","racecar","car"]

Output: ""

Explanation: There is no common prefix among the input strings.

 

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        li = []
        for string in strs:
            li.append(len(string))
        min_l = min(li)
        res = [] 
        i = 0
        while i < min_l: 
            filter_string = [string[i] for string in strs]
            if len(set(filter_string)) == 1:
                res.append(filter_string[0])
            else:
                break
            i+=1 
        return ''.join(res)