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: ["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.

class Solution(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        common= ''
        if len(strs)==0:
            return common
        if len(strs)==1:
            return strs[0]
        
        str0 = strs[0]
        flag = True
        for index in range(len(str0)):
            letter = str0[index]
            for str in strs[1:]:
                if len(str)<=index or str[index] != letter:
                    flag = False
                    break
            if not flag:
                break
            common+=letter
            
        return common
                
                

 

来源：https://blog.csdn.net/barryzhou/article/details/99557436