image.png

解法一（32 ms 94.75%）：

class Solution(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        if len(strs)==0:
            return ""
        
        L=[]
        s=set()
        count=0
        for i in strs:
            L.append(len(i))
        length=min(L)
    
        j=0

        while j<length:
            for i in range(len(strs)):
                s.add(strs[i][j])
            if len(s)==1:
                s = set()
                count+=1
                j+=1
                continue
            else:
                break

        return strs[0][0:count]