14. Longest Common Prefix

\14. Longest Common Prefix

Easy

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:

1 2	Input: ["flower","flow","flight"] Output: "fl"

Example 2:

1
2
3

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

终极改良版

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        if len(strs) == 0: return ''
    
        prefix = strs[0]
        for s in strs[1:]:
            prefix = self.same(prefix, s)
            if not prefix: return ''
        return prefix
        
    def same(self, s1, s2):
        res = ''
        if not s1 or not s2: return res
        for i in range(min(len(s1), len(s2))):
            if s1[i] != s2[i]:
                return s1[:i]
        return s1 if len(s1) <= len(s2) else s2