题目描述：

答案：

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        a= len(strs)
        if not str:
            return ""
        b = strs[0]
        c=len(b)
        for i in range(c):
            for j in range(1,a):
                if i ==len(strs[j]) or b[i] != strs[j][i]:
                    return b[0:i]
        return b

c此处：if a == 0 与if not str 相同